Answer : The ratio of effusion rates for helium and argon is 3.2 : 1
Solution : Given,
Molar mass of Helium = 4 g/mole
Molar mass of Argon = 40 g/mole
Rate of effusion : It is defined as the rate of effusion of a gas is inversely proportional to the square root of the molar mass of the gas.
Formula used :
where, M is the molar mass.
Now put all the given values in this expression, we get
Therefore, the ratio of effusion rates for helium and argon is 3.2 : 1
Answer: the last option, positive charge occupies a very small volume in the atom.
Explanation:
1) Earlier, JJ Thomson demonstrated that the electrons were subatomic particles and proposed the plum pudding model, in which the electrons are embedded in a positve mass. This model did not explain a lot of facts and was soon replaced.
2) Ernest Rutherford's experiments demonstrated the existence of the atomic nucleus: a tiny region with most of the mass of the atom and the positive charge.
3) Rutherford came up with this conclusion after the amazing results of the gold foil experiment which showed that some α particles (helium nucleii, which have positive charge) bounced off instead of pass through or being slighted deflected.
The bouncing of the α partilces, was infered to be the result of the repulsion by massive positive charge concentrated in small regions, this is the nucleus of the atom.
Answer:
B) any complex thing with properties normally associated with living things
2. I believe it would be two but then again this is an incomplete answer so it is not two. It's probably going to be 3. Or 1. Because I took this test before a while back and I'm almost a 100% sure it's 1 or 3. Hope this helps slightly!
Answer:
0.305 mol
Explanation:
Ca(NO) is not a molecule. I think you meant to type Ca(NO3)2, which is calcium nitrate.
The moles of a compound is equal to is mass divided by its molar mass.
The molar mass of Ca(NO3)2 is 164.09 g/mol.
50.0 / 164.09 = 0.305
