Scientists find out about atoms before technology from X-ray
There are three ways that scientists have proved that these sub-atomic particles exist and they are direct observation, indirect observation or inferred presence and predictions from theory or conjecture and scientists in the 1800's were able to infer a lot about the sub-atomic world from chemistry.
If X-rays let chemists peer at the structure of atoms, scanning tunneling microscopes finally revealed the atoms themselves scientists believed that atoms were uniform, solid, hard, incompressible, and indestructible and that they moved in infinite numbers through empty space until stopped and differences in atomic shape and size determined the various properties of matter.
Know more about atoms
https://brainly.com/question/1566330
#SPJ1
Question 1 of 7
Which sentence correctly explains the change that occurs when ice melts?
Ice melting is a physical change, and the state of the substance remains the same.
Ice melting is a physical change, and the mass of the substance remains the same.
оо оо
Ice melting is a chemical change, and the state of the substance remains the same.
Ice melting is a chemical change, and the mass of the substance remains the same.
Answer:
Explanation:B ice melting is a phiyscal change and the mass of the substance remains the same
Answer:
b
Explanation:
How many atoms is 59.6 Liters of He gas at STP?
Gustavo and Beatriz are pushing on a door in opposite
directions. If the door does not move, the forces are
The net force in this scenario would be Answer: balanced and zero
Answer:
Correct
Explanation:
Balanced forces are always zero!
Answer:
Balanced
Zero
Explanation:
A mixture of 80.0 g of oxygen and 80.0 g of helium has a total
pressure of 0.1800 atm. What is the partial pressure of each gas?
Answer:
Partial pressure of O₂ = 0.0198 atm
Partial pressure of He = 0.1584 atm
Explanation:
Given data:
Mass of oxygen = 80.0 g
Mass of helium = 80.0 g
Total pressure = 0.1800 atm
Partial pressure of each gas = ?
Solution:
First of all we will calculate the number of moles.
Number of moles of oxygen:
Number of moles = mass/molar mass
Number of moles = 80.0 g/ 32 g/mol
Number of moles = 2.5 mol
Number of moles of helium:
Number of moles = mass/molar mass
Number of moles = 80.0 g/ 4 g/mol
Number of moles = 20 mol
Total number of moles = 20 mol + 2.5 mol = 22.5 mol
Mole fraction of O₂ = 2.5 mol/ 22.5 mol = 0.11
Mole fraction of He = 20 mol / 22.5 mol = 0.88
Partial pressure:
Partial pressure of O₂ = 0.11× 0.1800 atm = 0.0198 atm
Partial pressure of He = 0.88 × 0.1800 atm = 0.1584 atm
4. A scientific theory is
1. a well-tested explanation for a widely accepted hypothesis
2. a well-tested explanation for a broad set of observations
3. a proven explanation for the results of multiple experiments
4. a hypothesis that has stood the test of time
Answer:
Option 1
Explanation:
Most of Earth's atmosphere is made up of nitrogen gas. Nitrogen can also
exist as a solid, liquid, or plasma. Four samples of nitrogen are each in a
different state but have the same mass. Which statement about the relative
amounts of thermal energy in the samples is true?
O A. The sample of solid has more energy than the sample of gas.
B. The sample of liquid has more energy than the sample of solid.
C. The sample of plasma has less energy than the sample of gas.
D. The sample of liquid has less energy than the sample of solid.
The sample of the liquid has more energy than the sample of solid. Hence, option B is correct.
What is thermal energy?Thermal energy refers to the energy contained within a system that is responsible for its temperature.
The particles in the liquid are the same as in the solid but they have more energy. To melt solid energy is required to overcome the attraction between the particles and allow them to pull them apart. The energy is provided when the solid is heated up.
Hence, option B is correct.
Learn more about thermal energy here:
https://brainly.com/question/11278589
#SPJ2
Pls Help! 100 Points!!!!!
Which of the following correctly compares the radii of F and F−?
A) F has a smaller radius than F− because an additional electron causes greater repulsion in F−.
B) F has a larger radius than F− because an additional electron causes greater repulsion in F.
C) F has a smaller radius than F− because F− has an additional energy shell.
D) F has a larger radius than F− because F has an additional energy shell.
F has a smaller radius than F− because F− has an additional energy shell correctly compares the radii of F and F−. The correct option is C.
Thus, Compared to oxygen, fluorine is a stronger electronegative element. The outermost electrons of fluorine are gripped by the nucleus more tightly than oxygen because fluorine has a high electronegativity.
It takes more energy to remove the outermost electron of fluorine than it does to remove the outermost electron of oxygen. Fluorine has a higher ionization energy than oxygen as a result.
An atom's energy is determined by how much energy it gains or loses as a result of chemical processes that result in electron loss or gain. Exothermic reactions are those in which energy is released, and endothermic reactions are those in which energy is absorbed.
Exothermic reactions produce negative energy, which is why energy is given a negative sign.
Thus, F has a smaller radius than F− because F− has an additional energy shell correctly compares the radii of F and F−. The correct option is C.
Learn more about Exothermic reactions, refer to the link:
https://brainly.com/question/18523044
#SPJ2
A 7-kg bowling ball is rolled down a lane while a 10-kg cart remains at rest. Which has the greatest inertia?
Im sorry but I have the same question tell me when you figure it out please
Which of the following elements will lose electrons to form an
ion? Check all that apply.
Р
Fe
Pb
Se
Elements that will loose electron as so that ion can be formed are; Fe and Pb.
Fe ( iron ) and Pb ( Lead) are both metals and metals will always loose electron so that they can turn to postively charged ion, and this ion is regarded as Cation.Phosphorus (P) is a non- metal, it will only gain electron and turn to a negatively charged ions, this ion is regarded as Anion.Therefore, Metals usually lose electron while non- metals accept the electron.
Learn more at:
https://brainly.com/question/13794764?referrer=searchResults
10. What mass of methane gas (C2H6) is 6.10 x 1024 molecules?
Answer:
10 to the 24 power
Explanation:
Type in the name of the following compounds. Be sure to use the periodic table if needed.
the answer is Sulfur dioxide
Answer:
Sulfur Dioxide
Explanation:
hope this helps:)
An ice cube melts in the hot sun. Is this exothermic or endothermic and
why?
Answer:
Endothermic
Explanation:
In order to melt the ice cube, heat is required, so the process is endothermic. Endothermic reaction In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings by the reaction.
Unsanitary meat processing, poisonous additives, and false claims about the efficacy of drugs (i.e., "snake oil") resulted in the original Food
and Drugs Act and Meat Inspection Act in 1906.
True or False
Unless otherwise instructed, you may use the periodic table in the Chemistry: Problems and Solutions book for this question.
Which explanation accounts for why carbon monoxide is not a polar molecule?
The electronegativity differences between carbon and oxygen are not very large.
Carbon and oxygen do not form ions.
Carbon is a metal, and oxygen is a nonmetal.
There are no hydrogen atoms in the molecule.
Answer:
The electronegativity differences between carbon and oxygen are not very large.
Explanation:
Between the atoms of carbon monoxide exists a covalent bond which attaches the carbon to the oxygen.
In this type of bonding, both atoms shares a given number of valence electrons to attain chemical stability.
A substance is polar when there is a distinct charge separation between the species.
For covalent bonds, the electronegativity difference plays in important role in determining the polarity of the compound. When the difference is large, the compound will be polar but when the difference is very small or zero, no polarity will exist.
In between carbon and oxygen of carbon monoxide, the electronegativity difference is very low.
Solid nickel reacts with aqueous lead (II) nitrate to form solid lead. What is the net ionic equation for this reaction? • Hint: In this reaction, nickel exhibits its most common oxidation state of +2. • Be sure to include the charge for each ion in the net ionic equation. Provide your answer below: (s) + (aq) → *(n)
Answer:
Pb²⁺(aq) --> Ni²⁺(aq)
Explanation:
The equation of the reaction is given as;
Ni(s) + Pb(NO₃)₂(aq) --> Pb(s) + Ni(NO₃)₂(aq)
In writing the ionic equation, we break the aqueous compound into ions. The solid and liquid compounds are ignored.
We have;
Pb²⁺(aq) + NO₃²⁻(aq) --> Ni²⁺(aq) + NO₃²⁻(aq)
Canceling the spectator ions;
Pb²⁺(aq) --> Ni²⁺(aq)
Answer:
Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)
Explanation:
The complete ionic equation of this reaction is
Ni(s)+Pb2+(aq)+2 NO−3(aq)→Ni2+(aq)+2 NO−3(aq)+Pb(s)
The nitrate ions are spectator ions and can be removed from the equation, giving us
Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)
substance in which two or more atoms are bonded together.
molecule(s)
two or more atoms touching means they are connected as molecules which also make up compounds
The table below shows the average seasonal relative humidity during the summer in four locations:
Relative Humidity
Location Average Seasonal Relative Humidity (%)
A
76
81
с
60
D
98
B
Which location is most likely to experience frequent summertime storms? (3 points)
Location A
Ob
Location B
Oc
Location C
Od
Location D
Answer:
C
Explanation:
It’s the lowest to create storms
What is the relationship between pressure and temperature
Answer:
The Pressure Temperature Law. This law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature. With an increase in temperature, the pressure will go up.
Explanation:
7) If the mass of an object is 20 g and its volume is 25 L. What is the density of this object? 1 8) What is the difference between accuracy and precision? Copy and paste a picture of something that accurate but not precise and also something that is precise, but not accurate. 9) What is the formula for percent error?
this is due under 30 mins, please help
Answer:
Accuracy is the closeness of a measured value to the accepted or exact value. The precision of a tool is the smallest unit of measure the tool provides. The smaller the units a tool can measure, the more precise the tool. A measurement can be precise and not be accurate.
Explanation:
Fireworks explode above your
head. Is this exothermic or
endothermic and why?
Plzzzz answer quick
An excited electron of hydrogen emits the least energy when it drops from 1 point
quantum levels *
Level 4 to level 2
level 5 to level 1
level 2 to level 1
O level 2 to level 5
Answer:
sorry to do this but I really needed some points to ask my question from someone else so that's why I am doing so really sorry and thank you for free points
The number of atoms of any element in the given chemical formula is the number that is written on the foot of the symbol of that element. Therefore, the correct option is option C.
What is atom?Atom is the smallest particle of any matter. Atom combines to form element and element combine to form molecule or compound.
Atom consists of electron, proton and neutron. The total mass of atom is inside the nucleus. Inside the nucleus proton and neutron is there. So calculate mass of an atom, total mass of all protons is added to the total mass of neutron. Electrons revolve around the nucleus.
If an electron of hydrogen gets excited and drops from energy level 2 to level 1 to release least energy. The level shows the energy levels.
Therefore, the correct option is option C.
Learn more about atoms, here:
https://brainly.com/question/13518322
#SPJ2
10 The rate of the reaction between hemoglobin (Hb)
and carbon monoxide (CO) was studied at 20°C.
The following data were collected with all
concentration units in u mol/L. (A hemoglobin
concentration of 2.21 u mol/L is equal to
2.21 x 10 mol/L.)
[Hblo [CO),
Initial Rate
(u mol/L) (u mol/L) (u mol/Ls)
2.21
1.00
0.619
4.42
1.00
1.24
4.42
3.00
3.71
(a) Determine the orders of this reaction with
respect to Hb and CO.
(b) Determine the rate law.
(c) Calculate the value of the rate constant.
(d) What would be the initial rate for an
experiment with [Hb]o =3.36 u mol/L
[CO] =2.40 4 mol/L?
Answer:cookie
Explanation:
Hello I was wondering if anyone knew how to draw the molecular geometry of fentanyl. I already did the Lewis structure.
Answer:
i dont
Explanation:
Predict and write the charges and symbols of the monatomic ions formed by the following atoms: bromine rubidium
Answer: The monoatomic ions formed by bromine and rubidium are [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.
Explanation:
When an atom accepts an electron negative charge is created on atom and is called as anion. When atom loses an electron positive charge is created on atom and is called as cation.
The atomic number of bromine and rubidium is 35 and 37 respectively. So, the number of electrons is equal to 35 and 37 respectively. Bromine will gain one electron and rubidium will lose one electron to attain stable electronic configuration to form [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.
[tex]Br:35:1s^22s^22p^63s^23p^64s^23d^{10}4p^5[/tex]
[tex]Br^-:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]
[tex]Rb:37:1s^22s^22p^63s^23p^64s^23d^{10}4p^63s^1[/tex]
[tex]Rb^+:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]
Which of the following statements about atomic mass is true? (help asap)
A. It represents the number of protons
B. It is the relative amount of mass of the element
C. It is the whole number used to numerically order the elements
D. It equals the number of electrons when the element is a neutral atom
Answer:
B
Explanation:
Because the atomic mass is the mass of a single atom of a chemical elements
I need the answer to this multiple-choice
A student is conducting an experiment to see which material, when placed in a closed circuit, will still allow a light bulb to light up. With which material would the student have success?
A.sulfur
B.copper
C.glass
D.wood
The student would have success in experiment with using copper in a closed circuit as it allows conduction and is a good conductor of electricity.
What is conduction?Conduction is defined as a process as a means of which heat is transferred from the hotter end of the body to it's cooler end.Heat flows spontaneously from a body which is hot to a body which is cold.
In the process of conduction,heat flow is within the body and through itself.In solids the conduction of heat is due to the vibrations and collisions of molecules while in liquids and gases it is due to the random motion of the molecules .
When conduction takes place, heat is usually transferred from one molecule to another as they are in direct contact with each other.There are 2 types of conduction:1) steady state conduction 2) transient conduction.According to the type of energy conduction is of three types:
1) heat conduction
2) electrical conduction
3)sound conduction
Learn more about conduction,here:
https://brainly.com/question/12136944
#SPJ2
what can chemically be broken down into a simpler substance
Answer: ea sports
Explanation:
A compound is a substance that contains two or more elements chemically combined in a fixed proportion. However, it is not an element because it can be broken down into simpler substances – carbon and hydrogen. ... Recall that the components of a mixture can be separated from one another by physical means.
What is the final concentration of a solution prepared by diluting 35.0 mL of 12.0 M HCl to a final volume of 1.20 L
Answer: The final concentration of a solution is 0.350 M
Explanation:
According to the dilution law,
[tex]C_1V_1=C_2V_2[/tex]
where,
[tex]C_1[/tex] = concentration of concentrated acid solution = 12.0 M
[tex]V_1[/tex] = volume of concentrated acid solution = 35.0 ml
[tex]C_2[/tex] = concentration of diluted acid solution= ?
[tex]V_2[/tex] = volume of another acid solution= 1.20 L = 1200 ml
( 1L=1000ml)
Putting in the values:
[tex]12.0\times 35.0=C_2\times 1200[/tex]
[tex]C_2=0.350M[/tex]
The final concentration of a solution prepared by diluting 35.0 mL of 12.0 M HCl to a final volume of 1.20 L is 0.350 M
PLEAS HELP ASAP WILL MARK BRAINLIST
Answer:
Carbon
Explanation: