Answer:
Sodium has 11 protons and Magnesium has 12. The way that the periodic table is set up doesn't allow for any elements to be in between. The element would have to have 11.5 protons, which is impossible
There is two different types but i’ll just do both meanings just incase.
Graham's Law of Diffusion: the rate of diffusion of one gas through another is inversely proportional to the square root of the density of the gas.
Graham's Law of Effusion: the rate of effusion of a gas is inversely proportional to the square root of the density of the gas.
hopes this helps..!
The answer is 3). This is because elements are the simplest form of a substance, and cannot be broken down any further. Compounds on the other hand are much more complex than elements and can be broken down INTO elements.
For example, Na, sodium, is an element and cannot be broken down further. H2O, water, is a compound and can be broken down into Hydrogen and Oxygen.
Answer:
613 mg
Explanation:

Number of fargday's 
Here, I = 9.20 A
t = 10.5 min
= 10.5 x 60 seconds
So, 

= 0.0208 F
Here, 2e, 2F
2F = 1 mol of Ni

1 mol = 59 gm of Ni
0.0104 mol = 59 x0.0104 gm Ni
= 0.613 gm Ni
= (0.613 x 1000 ) mg of Ni
= 613 mg of Ni
There are 2 moles of O stones present in 88 grams of CO2. Why? Well, we can find the amount of moles present in 88 grams of CO2 by dividing the mass by the molar mass. The mass of CO2 comes out to be 88 grams. The molar mass of CO2 comes out to be 44 grams. Because 88 is the mass of CO2 and 44 is the molar mass of CO2, we can divide 88 by 44 to identify that there are 2.0 moles of O atoms present in 88 grams of CO2.
Your final answer: There are 2.0 moles of O atoms present in 88 grams of CO2. Your final answer to this question is D, or 2.0 moles. If you need to better understand, let me know and I will gladly assist you.