Answer:
The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).
Explanation:
They are called alkali metals because they are in the alkali group.
Each of the atoms in alkali earths metal Family( group 2) has ___ valence Electrons .
Pleasee help I’ll mark you as brainlister
Fill in the blank
Answer:
the answer is 2 valence electrons
I need help with this. Plzzzzz
Answer:what do you nned help with
Explanation:
I need help with these two questions
halogens have 7
allali have 2
noble gases have 8
K = 1
P = -3
Ra= 7
Cl = -1
N = 5
O = 6
Are the oldest rocks in the canyon found near the bottom
Answer: yes they are
Explanation:
because its so hot and the heat just stays at the bottom
How many particles in 32.0 liters of helium
Number of particles : 8.603 x 10²³
Further explanationStandard conditions for temperature and pressure are used as a reference in certain calculations or conditions
Assumption⇒ Standard Conditions
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.
1 mol = 6.02 x 10²³ particles (atoms, ions, or molecules)
32.0 liters of Helium
[tex]\tt mol=32:22.4=1.429[/tex]
Number of particles :
[tex]\tt 1.429\times 6.02\times 10^{23}\\\\=8.603\times 10^{23}[/tex]
2.18 x 10^6 ng = 2.18 x 10^? mg
Answer:
2.18 * 10^12 mg
Explanation:
1 nanogram [ng] = 10^6 milligram [mg]
2.18 * 10^6 ng/ 1 ng = X mg / 10^6 mg
X mg = 2.18 * 10^12 mg
Answer:
2.18 * 10^12 mg
Explanation
What is a hypothesis?
O proof and evidence of a scientific fact
O a question about nature and how it works
a series of steps to carry out an experiment
O a possible explanation of or answer to a scientific question
Answer:
The 4th option
a possible explanation of or answer to a scientific question
Explanation:
Answer:
A hypothesis is a question about naturre and how it works
Which statement offers an explanation for why some parts of John Dalton's atomic theory were proven to be false?
Scientists today are more diverse and have more educational training
Mistakes were made in key calculations during experimenting
Extensive repeated testing was not completed to verify the results
Technology available at that time was limited.
Answer:d
Explanation:
Answer:
The answer is D
Explanation:
I took the test!
Complete a write up about the elements in Ammonia and explain how the elements bounded to create the new substance.
Answer:
Explanation:
Ammonia consist of nitrogen and hydrogen.
Chemical equation:
N₂ + H₂ → NH₃
Balance chemical equation:
N₂ + 3H₂ → 2NH₃
We can see that nitrogen and hydrogen react with each other and from ammonia.
Nitrogen is present in group 5A. The atomic number of nitrogen is 7. Its atomic mass is 14 amu. It has 5 valence electron.
Electronic configuration:
N₇ = 1s² 2s² 2p³
we can see there are five electron in outer most shell. Thus, nitrogen needs three more electrons to complete the octet. When it combine with other atoms it gain three electron from them
While hydrogen is present in group 1A. It has one valence electron. In ammonia (NH₃) when nitrogen react with hydrogen it gain three electrons thus three atoms of hydrogen combine with one atom of ammonia because one hydrogen atom can share only one electron. Covalent bond is formed between nitrogen and hydrogen and new substance formed is called ammonia.
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Which type of matter is always made up of only one kind of atom?
A. Element
B. Mixture
C. Molecule
D. Compound
pls answer fast
Answer:
A. element
Explanation:
Answer: Element
Explanation: A substance that is composed of only one type of atom is called an element. At this point, what should amaze you is that all forms of matter in our universe are made with only 118 different building blocks.
How
myny moles are present in 5.6x1022 atoms of Ne? (0.09 moles Ne)
Sot ne10.05
Answer:
mole = no of atoms/ 6.02E23.... so therefore answer= 5.6E22/6.02E23= 0.093✨
Reducing child __________, or rate of death, is one of the primary goals of the UN’s Millennium Development Goals.
A.
mortality
B.
maternity
C.
infirmity
D.
infection
Answer: A
Explanation: Mortality means death. And it is a primary goal of Development Goals
Reducing child mortality, or rate of death, is one of the primary goals of the UN’s Millennium Development Goals and the correct option is option A.
What is Mortality?Mortality is defined as the state of the individual being dead. The mortality rate is the death rate of a population which is calculated on the basis of the deaths in the particular region.
Mortality as one of the components of demography is measured as mortality rate.
Mortality meaning provides the basis for mortality rate and its estimation. Mortality is the possibility of and susceptibility to death, and hence, the rate of mortality or the death rate is the measurement of the number of deaths that occur in a particular population, scaled to the size of that population per unit of time.
Therefore, Reducing child mortality, or rate of death, is one of the primary goals of the UN’s Millennium Development Goals and the correct option is option A.
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Examine the layers of rock. Identify and explain which layer contains the youngest fossils.
Earth layers with fossiles in each labeled top to bottom A to D.
Answer:
Layer A is the youngest
Explanation:
It is at the top, it has all of the dinosaur bones which got buried after earth got hit with an asteroid and they went extinct. Layer D started it and all of these years dirt, soil, and fossils have been gathering making each layer before older and older.
Which chemical equation best represents the Law of Conservation of
Mass?
O H+ 0 -> H20
H2 + 02 --> H20
2H2 + O2 --> 2H20
H2 + O2 --> 2H,02
2H₂ + O₂ ⇒ 2H₂O
Further explanationConservation of mass states that
In a closed system, the masses before and after the reaction are the same
So it can be concluded
mass of the reactants = mass of the productsmass cannot be created or destroyedThe number of atoms involved in a reaction remains the same⇒ number of moles also the samechemical equation in balanced formSo let's see which of the several options , which one has the same number of atoms on both sides of the equation
2H₂ + O₂ ⇒ 2H₂O
H ⇒ left 4, right 4
O ⇒ left 2, right 2
so the equation is in balance and represents the Law of Conservation of
Mass
if an object has a mass of 30 grams and a volume of 6 cubic cm. what is its density
Answer:
5
Explanation:
mass/volume = density
30/5 = 5
Can you tell me the Valence Electron of each element?
Answer:
Lithium oxide.......................
Explanation:
6. magnicium chloride
2.Barium chloride
3. calcium nitride
4. lithium oxide
5. Aluminium sulphide
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mortal kombat 11 or the new cyber punk which do u think is better
Answer:
personally I like the mortal kombat 11 better
Answer:
mortal combat 11.
I beg you please please I beg you help me please I’m litterly crying please :(
A student determines the density of an element to be 2.73 g/cm 3 . If the accepted value is 2.70 grams per cm 3 , what is the student's percent error? Identify the element. What is the boiling of this element in Celsius degree
Answer:
Explanation:
percentage error = error x 100 / correct value
= (2.73 - 2.70) x100 / 2.70
= 1.11 %
The element is Aluminium whose density is 2.702 grams / cc
Boiling point of Aluminium = 2519⁰C .
put 34,100,000 in scientific notation
Answer:
3.41 x 10^7
Explanation:
please help asappp
will mark branliest!!
Answer:c
Explanation:
Answer:
C is the answer
are in the outermost energy level
psoriasis is a disease that causes a red rash on the skin. which body system does psoriasis affect?
a. respiratory
b. integumentary
c. immune
d. digestive
e. circulatory
Answer:
The answer to this question is integumentary.
Explanation:
The answer is that because that is your skin area and so if you have a rash then if will affect that part.
It's b. integumentary
I got the test right
Which of the following is the abbreviation for the element Gold?
Answer:
Au
Explanation:
trust me, the abbrevation for gold is Au. chemicaly, Medicaly, and in dentistry
What is the relationship between the atomic mass of an element and a mole of that element's atoms?
Answer:
Each ion, or atom, has a particular mass; similarly, each mole of a given pure substance also has a definite mass. The mass of one mole of atoms of a pure element in grams is equivalent to the atomic mass of that element in atomic mass units (amu) or in grams per mole (g/mol).
Explanation:
The relationship between the given terms is provided below throughout the below segment.
One mole of such a component's atomic weights is approximately equivalent to that component's atomic mass. This same atomic mass of the oxygen element, for example, is about 16g. As a result, one mole containing oxygen atoms equals 16g of oxygen ([tex]O_2[/tex]). 1 mole containing oxygen atoms weighs 16g.We can say that,
→ [tex]1 \ mole \ in \ gram \ of \ an \ element = Atomic \ mass \ of \ an \ element[/tex]
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Which of the following is the end product of a natural
radioactive series?
Answer:
Lead
Explanation:
Lead (Pb) is the end product of every natural radioactive series.
235/92 U + 1/0 n -> 138/55 Cs + 96/37 Rb + 2 1/0 n
what kind of reaction?
Answer:
Nuclear fission
Explanation:
This reaction is called a nuclear fission reaction. In this reaction, a radioactive decay process occurs in which a heavy nucleus spontaneously disintegrates into two lighter nuclei and several neutrons, with the release of a large amount of energy.
The imbalance between the number of neutrons and protons is responsible for this spontaneous disintegration. Until a stable daughter cell forms, the reaction proceeds.You are a high school track & field coach and you have a young female athlete who is running a competitive mile pace (5:20). This would make her competitive at the state and national level. You want to help this athlete to maintain and even increase her competitive potential. What would you do?
Answer:
By ensuring she is giving speed endurance training
Explanation:
Speed endurance training would be the most ideal in helping an athlete to maintain and even increase her competitive potential.
The speed endurance training would help the athlete maintain and attain a high speed for a longer duration of time.
This would make the athlete get used to running an improved time for much longer distances.
how many atoms is in a molecule of omega 3 fatty acid
Answer:
There are 18 carbon atoms in a molecule of omega 3 fatty acid
Explanation:
19. Chemical properties can be used to
(1) differentiate between two compounds
(2) determine the temperature of a substance
(3) determine the density of a substance
(4) differentiate between two neutrons
Answer:differentiate between two compounds i think!
Explanation: taking a test!
Answer:(1) differentiate between two compounds
Explanation:
A Chemical property tells us the characteristics of a particular matter or substance after a chemical change. This property helps us to differentiate a compound from another or differentiate elements or substances. Examples of a Chemical property are acidity, reactivity and heat, etc .
For example to differentiate between Water H2O and Hydrogen peroxide, H202
Even though they are made up of oxygen and hydrogen. Hydrogen peroxide (H2O2), has more(1) oxygen than water (H2O).
Using Acidity as a chemical property to differentiate these substances
Water, H20 is amphoteric in nature ie having both acidic and basic properties, while H202 is a weak acid.
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