Answer:
12C and 16O
Explanation:
Here, we want to select which of the options are NMR inactive. For an isotope to be NMR inactive, then the net nuclear spin is zero.
What this means is that the number of proton present coupled with the number of neutrons are an even number pair.
What we are saying here is that the number of protons is an even number while the number of neutrons too is an even number. So the net nuclear spin in this case is zero.
in the case of oxygen, we have 8 protons and 8 neutrons. This makes the nuclear spin zero and consequently makes the isotope NMR inactive.
Same is in the case of carbon. There are 6 protons and 6 neutrons and this also makes nuclear spin zero .
In all the other isotopes in the question, we have odd number even number or even number odd number pairs of protons and neutrons.
PLEASE HELP ME, I have no idea how to do this :(
Answer:
molar mass: 151.165
Explanation:
mass of Carbon is 12.011 amu
mass of Hydrogen is 1.008
mass of Nitrogen is 14.007
mass of Oxygen is 15.999
you make the calculations like this...
[tex](12.011 \times 8) + (1.008 \times 9) + (14.007) + (15.999 \times 2) = 151.165amu[/tex]
Humans breathe about 500 mL of air per breath and take about 12 breaths per minute during normal activities. If a person is exposed to an atmosphere containing benzene at a concentration of 10 ppm (by volume), how many grams of benzene will be deposited in the lungs during an 8-hour shift if all the benzene that enters remains in the lungs
Answer:
mass of benzene in the lungs = 28.8 g of benzene
Explanation:
Volume of air breathed per hour = 500 mL * 12 * 60 = 360000 ml = 360 Litres of air
In 8 hours, volume of breathed air = 360 L * 8 = 2880 Litres of air
Concentration of benzene in air = 10 ppm
Note: 1 ppm = 1 mg per liter (mg/L)
10 ppm = 10 mg/L
Therefore, mass of benzene in the lungs in an 8-hour shift = 10 mg/L * 2880 L
mass of benzene in the lungs = 28800 mg
Converting to grams = 28800/1000
mass of benzene in the lungs = 28.8 g of benzene
Which of these statements is supported by the results of Thomson’s experiment? Check all of the boxes that apply.
Atoms are indivisible.
Cathode rays are made up of negatively charged particles.
Atoms contain negatively charged particles.
Answer: Cathode rays are made up of negatively charged particles.
Atoms contain negatively charged particles.
Catie set a glass of hot water and a glass of cold water on the kitchen table and let them sit for one hour. How will the particle motion within the glasses change?A.The particles in both glasses will speed up.B.The particles in both glasses will slow down.C.The particles in the hot water will slow down, while the particles in the cold water will speed up.D.The particles in the hot water will speed up, while the particles in the cold water will slow down.
Answer:
C.The particles in the hot water will slow down, while the particles in the cold water will speed up
Explanation:
Heat causes changes in the molecules of substances when applied to them. The molecules of water, as a case study used in this question, when heated has an increased kinetic energy which causes its particles to move faster i.e. speed up. Also, when water is freezed or cold, it's particles move slower i.e. slow down due to decreased kinetic energy.
Hence, when a hot glass of water and a cold glass of water are placed on a kitchen table for 1 hour, they don't remain in their respective thermal state.
- The hot water (with an increased movement of molecules) begin to cool down, hence, its particles slows down as it gets cold or less hot.
- Likewise, the cold water (with a decreased movement of molecules) begins to get warmer, hence, it particles speedens up as it gets warmer.
Therefore, The particles in the hot water will slow down, while the particles in the cold water will speed up
Which statement best describes the polarity of SCL4F2?
a. The molecule is always polar.
b. The molecule s always nonpolar.
c. Depending on the arrangement of outer atoms, this molecule could be polar or nonpolar.
Answer: Depending on the arrangement of outer atoms, this molecule could be polar or nonpolar.
Explanation:
Polarity is when the electric charge that is leading to a molecule is being separated.
The polarity of SCL4F2 can either be polar or non polar and this depends on the arrangement of outer atoms. It is the arrangements of these outer atoms that'll help in the determination of its polarity.
The molecule SCl4F2 could be polar or nonpolar depending on the arrangement of outer atoms.
The molecule SCl4F2 could have different arrangements of outer atoms. That means that there are two possible arrangements of the molecule. Depending on which arrangement the outer Cl and F atoms have, the molecule cold be polar or nonpolar.
In the arrangement of SCl4F2 which could be polar is the one in which the dipoles in the molecule do not cancel out. In the other arrangement, the dipoles cancel out and the molecule is nonpolar.
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Select the answer from the drop-down, ranging from true or false.
Mixtures have components that are always in fixed ratios.
[ true or false ]
Compounds can only be separated physically.
[ true or false ]
The components of a mixture keep their unique properties.
[ true or false ]
Mixtures can be physically separated
[ true or false ]
Mixtures are pure substances
[ true or false ]
Compounds are pure substances
[ true or false ]
Answer:
False, False, True, True, False, True
Explanation:
Mixtures have components that are always in fixed ratios. FALSE. The ratio of components in a mixture is variableCompounds can only be separated physically. FALSE. Compounds can only be separated chemically.The components of a mixture keep their unique properties. TRUE. Mixtures can be physically separated. TRUE. Mixtures are pure substances. FALSE. Mixtures are formed by a mixture of 2 or more pure substances, not bonded chemically.Compounds are pure substances. TRUE.true? no false. ... no its true uhhhhh no gotta be false true. false. true. fase. gotta be tru false or maybe its true? nah its false
pls brainliest?
a nucleus with 4 protons has a positive charge of _____ PLEASE LET ME KNOW
Answer:
if were talking about berylium then the answer should be 2 because it wants to move 2 spaces back (losing electrons) to become a nobel gas so the answer is 2+
Explanation:
it has 2 valence electrons YW :)
A nucleus with 4 protons has a positive charge of +2.
What are Protons?Protons may be defined as the type of sub-atomic particles that are present in the nucleus of an atom along with the neutrons. These sub-atomic particles possess a positive charge in nature. It may be thought that protons are discovered by Ernest Rutherford.
Beryllium has a nucleus with 4 protons, which means that it has an atomic number of 4. This element belongs to the alkaline earth metals in group 2. Beryllium has the capability to lose two electrons in order to attain a noble gas configuration and occupy stability. It has an electronic configuration [tex]1s^2, 2s^2[/tex]. So, in order to make it octet fulfilled, it loses two electrons and becomes positively charged.
Therefore, a nucleus with 4 protons has a positive charge of +2.
To learn more about Protons, refer to the link:
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can some one help The function of the cell wall in a plant cell is Question 2 options: Allowing material to pass in and out of the cell Uses carbon dioxide, water and energy from the sun to make sugar Breaks sugar down into ATP which the cell can use for energy Provides support and protection for the cell
Answer:
the protection one
Explanation:
the cell wall acts a barrier
2. Report each of the following quantities to 3 significant figures. Use standard notation if possible, or
exponential notation if standard notation won't work.
a. 86,942
f. 56,018
b. 0.00621875
g. 0.003870
c. 107062.03
h. 15.9994
d. 4.00049
i. 12.011
e. 96
j. 2,000
Answer:
a. 86,942 = 8.69x10⁴
f. 56,018 = 5.60x10⁴
b. 0.00621875 = 6.22x10⁻³
g. 0.003870 = 3.87x10⁻³
c. 107062.03 = 1.07x10⁵
h. 15.9994 = 16.0
d. 4.00049 = 4.00
i. 12.011 = 12.0
e. 96 = 9.60x10¹
j. 2,000 = 2.00x10³
Explanation:
Hello,
In this case, rounding off each measurement to three significant figures, considering that if the fourth figure is five or more, the third one is rounded, we obtain:
a. 86,942 = 8.69x10⁴ (four places until the last digit and third digit is not rounded).
f. 56,018 = 5.60x10⁴ (four places until the last digit and third digit is not rounded).
b. 0.00621875 = 6.22x10⁻³ (three places until the first digit and third digit is rounded).
g. 0.003870 = 3.87x10⁻³ (three places until the first digit and third digit is not rounded).
c. 107062.03 = 1.07x10⁵ (five places until the last non-decimal digit and third digit is not rounded).
h. 15.9994 = 16.0 (those consecutive nines round the number to 16.0).
d. 4.00049 = 4.00
i. 12.011 = 12.0
e. 96 = 9.60x10¹ (exponential notation is needed since the number initially has two significant figures so an additional zero is added)
j. 2,000 = 2.00x10³ (three places until the last digit and third digit is not rounded).
Best regards.
The Avogadro constant is defined as
Answer:
Hope this may help you
How many moles are in 34.0 g of dinitrogen oxide?
Answer:
0.773 mole
Explanation:
From the question given above, the following were obtained:
Mass of dinitrogen oxide (N₂O) = 34 g
Mole of N₂O =.?
Next, we shall determine the molar mass of N₂O. This can be obtained as follow:
Molar mass of N₂O = (14 × 2) + 16
= 28 + 16 = 44 g/mol
Finally, we shall determine the number of mole in 34.0 g of dinitrogen oxide (N₂O) as follow:
Mass of dinitrogen oxide (N₂O) = 34 g
Molar mass of N₂O = 44 g/mol
Mole of N₂O =.?
Mole = mass /Molar mass
Mole of N₂O = 34/44
Mole of N₂O = 0.773 mole
Therefore, 0.773 mole is present in 34 g of dinitrogen oxide
I am timed please help
Answer:
compound
Explanation:
MgO is an inorganic compund :) The simplest explanation is that it's not an element b/c there's two elements (Mg & O) in the substance, and it's not a mixture b/c you can't easily separate the two elements.
Answer:
magnesium when magnesium is burnt by heat it forms an compound called magnesium oxide
How many Calories are there in 4600 Joules?
Answer:
1099.426
Explanation:
7. What must you do before you make a hypothesis?
Answer:
Ask a question?
Explanation:
look at the scientific method uwu
A 60.04 g sample of a compound of carbon, sulfur, hydrogen and oxygen is burned completely. Calculate the empirical formula if 44.8 L of water at STP and 88.0 g of CO2 is formed. In another experiment, a 15.00 g sample of the compound produced 1.00L SO2 at 25.0 oC and 3.05 atm. In a final experiment: 3.57 L of the compound at 2.33 atm and 25 o C weighted 35.0g Find the molecular formula of the compound.
Answer:
Empirical formula: C₂SH₄
Molecular formula: C₄S₂H₈
Explanation:
The empirical formula is the simplest whole ratio of atoms presents in an element.
The compound contains C, S and H, its empirical formula is CₐSₓHₙ. We need to determine a, x and n solving for the moles of each element, thus:
Moles H₂O - moles H-:
PV/RT = n
At STP, P is 1atm, and T is 273.15K:
1atm*44.8L / 0.082atmL/molK*273.15K
moles H₂O = 2 moles water = 4 moles of H
Because 1 moles of water contains 2 moles of H
Moles CO₂ = moles C:
88.0g CO₂ * (1mol / 44g) = 2 moles CO₂ = 2 moles C
The mass of carbon is:
2 moles * (12g/mol) = 24g
Mass of hydrogen:
4 moles * (1g/mol) = 4g
The mass of S is:
60.04g - 24g - 4g = 32.04g = 1 mole of S
Empirical formula is:
C₂SH₄Now, the moles of the compound in the final experiment are:
PV / RT = n
2.33atm*3.57L / 0.082atmL/molK*298.15K = 0.34 moles
-25°C = 298.15K. In gas laws you must use absolute temperature given in Kelvin-
These moles are in 35.0g. The molar mass of the compound is:
35.0g / 0.34 moles = 102.9g/mol
As the empirical formula is C₂SH₄ and weighs 60g/mol. Twice the empirical formula are the molecular formula:
C₄S₂H₈The Molecular formula of the compound: C₄S₂H₈
Empirical formula:It is the simplest whole number ratio of atoms present in a compound.The compound contains C, S and H, its empirical formula is CₐSₓHₙ. We need to determine a, x and n solving for the moles of each element, thus:Moles of H₂O= Moles of H:[tex]n=\frac{PV}{RT}[/tex]
At STP, P is 1atm, and T is 273.15K:
[tex]n= \frac{1atm*44.8L}{0.082atmL/molK*273.15K}[/tex]
Moles H₂O = 2 moles water = 4 moles of H
As, 1 moles of water contains 2 moles of H
Moles of CO₂ = Moles of C:88.0g CO₂ * (1mol / 44g) = 2 moles CO₂ = 2 moles C
We know,
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Mass of carbon is: [tex]2 moles * (12g/mol) = 24g[/tex]
Mass of hydrogen is: [tex]4 moles * (1g/mol) = 4g[/tex]
Mass of sulphur is: [tex]60.04g - 24g - 4g = 32.04g[/tex] = 1 mole of S
The derived Empirical formula will be: C₂SH₄
Now, the moles of the compound in the final experiment are:
[tex]n= \frac{PV}{RT}\\\\n=\frac{2.33atm*3.57L}{0.082atmL/molK*298.15K}\\\\ n= 0.34 moles[/tex]
These moles are in 35.0g. The molar mass of the compound is: [tex]\frac{35.0g}{0.34 moles} =102.9g/mol[/tex]
As the empirical formula is C₂SH₄ and weighs 60g/mol.
The empirical formula is two times the molecular formula: C₄S₂H₈
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6. Un volumen de 1.0 mL de agua de mar contiene casi 4 x 10-12 g de Au. El volumen total de agua en los océanos es de 1.5 x 1021 L. Calcule la cantidad total de Au (en gramos) existente en los océanos y su valor total en dólares. ( 1 onza = $ 948)
Answer:
The total amount of Au is $ [tex]2.0\times10^{24}[/tex]
Explanation:
Given that,
Mass of 1.0 ml of Au [tex]m=4\times10^{-2}\ g[/tex]
Total volume of water in oceans [tex]V=1.5\times10^{21}\ L[/tex]
We need to calculate the volume in ml
Using given volume
[tex]V=1.5\times10^{21}\times1000\ mL[/tex]
[tex]V=1.5\times10^{24}\ mL[/tex]
We need to calculate the total mass of Au
Using given data
[tex]1\ ml\ volume = 4\times10^{-2}\ g[/tex]
[tex]1.5\times10^{24}\ ml=4\times10^{-2}\times1.5\times10^{24}[/tex]
So, The total mass of Au is [tex]6\times10^{22}\ g[/tex]
The mass will be in ounce,
[tex]Mass=0.035274\times6\times10^{22}[/tex]
[tex]Mass=2.12\times10^{21}\ ounce[/tex]
The total amount of the Au Will be
[tex]Total\ amount=2.12\times10^{21}\times948[/tex]
[tex]Total\ amount=2.0\times10^{24}[/tex]
Hence, The total amount of Au is $ [tex]2.0\times10^{24}[/tex]
1)
Which of the following would a chemist be most likely to study?
A what happens when a moving car comes to a stop
B.
what happens when iron rusts in the presence of water
C. what happens when ice melts to form liquid water
D. what happens when light reflects from a shiny surface
Answer:
B. what happens when iron rusts in the presence of water
Explanation:
Chemistry is a branch of science involving the composition and changes of matter. In other words, a chemist, who is a trained specialist in the science of chemistry, seeks to answer questions related to properties of matter.
In this question, a chemist is most likely to study "what happens when iron rusts in the presence of water" because it involves a change in the chemical properties of a substance (iron) i.e. a chemical change. However, what happens when ice melts to liquid water is a physical change.
What is the symbol for the element that has 12 protons,14 neutrons, and 12 electrons
Answer:
mg
Explanation:
You bought a new car and estimated that your monthly payment would be $312. However, your actual payment amount is $325. How much error was in your estimate?
Please help me with this? :(
Answer:
1. Diagram C.
2. Diagram A.
Explanation:
1. Calcium atom, Ca has 20 protons and 20 electrons. On the other hand, Calcium ion, Ca^2+ has 20 protons and 18 electrons. This is true because the +2 charge on the calcium ion, Ca^2+ indicates that the calcium atom, Ca has loss 2 electrons.
From the above illustration we can say that calcium ion, Ca^2+ has the following:
Proton = 20
Electron = 18
Therefore, diagram C indicates calcium ion, Ca^2+.
2. Fluorine atom, F has 9 protons and 9 electrons. Fluoride ion, F¯ has 9 protons and 10 electrons. This is so because the –1 charge on the fluoride ion, F¯ indicates that the fluorine atom, F has gained 1 electron.
Thus, we can say that the fluoride ion, F¯ has the following:
Proton = 9
Electron = 10
Therefore, diagram A represent fluoride ion, F¯.
In a compound the elements are _____ together, whereas in a mixture the substances are blended together.
Answer:
bonded
Explanation:
Compounds are two elements bonded together.
A mixture is multiple substances blended together. The substances aren't bonded together and can easily be extracted from each other.
What should you do every time you are about to heat glassware on a hot plate?
Select one or more:
Check that there are no cracks in the glassware
Ensure that the glassware is designed for heating
Inspect the hot plate for frayed cords
0 Measure the height and width of the glassware
Answer:
Ensure that the glassware is designed for heating
Check that there are no cracks in the glassware
Inspect the hot plate for frayed cords
Explanation:
All except measuring the height and width of the glassware could cause hazards within the lab.
The first health care worker said, "Anatomy and Physiology makes the difference between me being a nurse and a ______ nurse?
Answer
The first health care worker said, "Anatomy and Physiology makes the difference between me being a nurse and a great nurse?
Explanation:
I got the correct answer
Question 1 (Multiple Choice Worth 2 points)
(01.01 LC)
The strength of gravitational force is affected by the distance between objects and which of the following?
O Weight
O Speed
O Density
O Mass
11. A sample contains 25% water and weighs 201 grams. Determine the grams of water in the
sample.
Answer:
[tex]m_{water}=50.25g[/tex]
Explanation:
Hello,
In this case, considering that the by-mass percent of water is:
[tex]\% m/m=\frac{m_{water}}{m_{sample}}*100\%[/tex]
Given such percent and the mass of the sample, we can find the mass of water in grams in the sample by solving for it as shown below:
[tex]m_{water}=\frac{\%m/m*m_{sample}}{100\%}\\ \\m_{water}=\frac{25\%*201g}{100\%}\\ \\m_{water}=50.25g[/tex]
Best regards.
A laser pointer used in the classroom emits light at 5650 Å, at a power of 4.00 mW. (One watt is the SI unit of power, the measure of energy per unit of time. 1 W = 1 J/s). How many photons are emitted from the pointer in 115 seconds?
Answer:
n = 1.3 x 10¹⁸ photons
Explanation:
First we need to calculate the amount of energy released in given time:
E = Pt
where,
E = Energy = ?
P = Power = 4 mW = 0.004 W
t = time = 115 s
Therefore,
E = (0.004 W)(115 s)
E = 0.46 J
Now, this energy can be given in forms of photons as:
E = nhc/λ
where,
n = No. of photons = ?
h = Plank's Constant = 6.626 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of light = 5650 x 10⁻¹⁰ m
Therefore,
0.46 J = n(6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(5650 x 10⁻¹⁰ m)
n = (0.46 J)/(3.5 x 10⁻¹⁹ J)
n = 1.3 x 10¹⁸ photons
Answer:
1.308 x 10¹⁸ photons were emitted from the laser pointer.
Explanation:
Given;
wavelength of the photon, λ = 5650 Å = 5650 x 10⁻¹⁰ m
power emitted by the source, P = 4 mW = 4 x 10⁻³ W
time of photon emission, t = 115 s
The energy of a single photon is given by;
E = hf
f = c / λ
[tex]E = \frac{h c }{\lambda}[/tex]
where;
c is speed of light = 3 x 10⁸ m/s
h is Planck's constant = 6.626 x 10⁻³⁴ Js
[tex]E = \frac{(6.626 *10^{-34}) (3*10^8) }{5650*10^{-10}}\\\\ E = 3.518*10^{-19} \ J[/tex]
Energy of the source (laser pointer) = P x t
= (4 x 10⁻³ W) (115 s )
= 0.46 J
If no energy is lost, then emitted energy by the source must be equal to total energy of then photons;
[tex]E_T = n E_{photon}\\\\n = \frac{E_T}{E_{photon}}\\\\n = \frac{0.46}{3.518*10^{-19}}\\\\n = 1.308*10^{18} \ photons[/tex]
Therefore, 1.308 x 10¹⁸ photons were emitted from the laser pointer.
Describe each highlighted bond in terms of the overlap of atomic orbitals. (If the highlighted bond is not a pi bond, select the blank option from the dropdown menu.) Compound 1: Molecular orbital type: _________ Atomic orbitals in the sigma bond: _________ Atomic orbitals in the pi bond: _________ Compound 2: Molecular orbital type: _________ Atomic orbitals in the sigma bond: _________ Atomic orbitals in the pi bond: _________
The image of the bonds are missing, so i have attached it.
Answer:
A) - Sigma bond
-Sp³ and Sp³
- None
B) - Sigma and pi bond
- Sp² of C and p of O
- p of C and P of O
Explanation:
A) For compound 1;
- the molecular orbital type is sigma bond due to the end-to-end overlapping.
- Atomic orbitals in the sigma bond will be Sp³ and Sp³
- Atomic orbitals in the pi bond would be nil because there is no pi bond.
B) For compound 2;
- the molecular orbital type is sigma and pi bond
-Atomic orbitals in the sigma bond would be Sp² of C and p of O
- The Atomic orbitals in the pi bond will be; p of C and p of O
Zirconium dioxide (ZrO2), sometimes known as zirconia, is a white crystalline oxide of zirconium. It can be used in oxygen sensors and fuel cell membranes because it has the ability to allow oxygen ions to move freely through the crystal structure at high temperatures. The ionic radius of Zr is 0.079 nm, and the ionic radius of Cl is 0.140 nm. What is the coordination number of ZrO2?a. 3b. 6c. 4
Answer:
The coordination number of ZrO₂ = 6
Explanation:
A crystal structure is determined by the ratio of ionic radii of the positive and negative ions present in the crystal.
The ratio of the radii of the positive(cations) and negative(anions) is called the limiting radius ratio and it gives the coordination number of the crystal.
Limiting radius ratio = radius of cation/radius of anion
For ZrO₂:
radius of Zr ion (Zr⁴⁺) = 0.079 nm; radius of O ion (O²⁻) = 0.140 nm
Limiting radius ratio = 0.079 nm/0.140 nm = 0.564
From tables, when the limiting radius ratio value is between 0.414 - 0.732, the coordination number is six and the shape of the crystal is octahedral.
Therefore, the coordination number of ZrO₂ = 6
indigestion tablets neutralise acid in the stomach. what does this tell you about indigestion tablets?
Answer:
It is basic.
Explanation:
Bases can neutralize acids.
Rounding 6.42 g to 2 significant figures
Answer:
6.4
Explanation: