Answer:
Sift the mixture to separate the rock from the iron filings, soil and salt.
You can then use a magnet to separate the iron filings from the salt and soil.
Afterwards, you can pour water into the remaining salt- soil mixture. Salt will dissolve but the soil will remain at the bottom of the water.
If you want to separate the salt from the water, you can boil it till all the water evaporates. The only thing that'd be left in the pan is salt.
The principal energy level at n=3 contains s,p,d orbitals in their valence shell.
Option(b);
<u>Explanation:</u>
"Principal energy level" is used to locate the no of electrons in each orbital to its atomic nucleus. These energy levels are denoted by the "principal quantum number" n.
There are four energy level of orbits available in this system. And the following shows different level of orbits and the no of electrons for each value of n
- At n=1, Orbital name=S, No of electrons=1
- At n=2, Orbital name=S, P, No of electrons=4
- At n=3, Orbital name=S, P, D, No of electrons=9
- At n=4, Orbital name=S, P, D, F, No of electrons=16
Answer:
98.78 g/mol.
Explanation:
<em>Thomas Graham</em><em> found that, at a constant temperature and pressure the rates of effusion of various gases are inversely proportional to the square root of their masses.</em>
∨ ∝ 1/√M,
where, ∨ is the rate of effusion and M is the atomic or molecular weight of the gas particles.
- For two different gases, unknown gas (1) and hydrogen (2):
∨₁/∨₂ = √M₂/√M₁.
∨₁/∨₂ = 1/7,
M₁ = ??? g/mol, M₂ = 2.01588 g/mol.
∴ (1/7) = (√2.01588)/(√M₁)
By squaring both sides:
∴ (1/7)² = 2/(M₁) = 0.02
∴ M₁ = 2.01588/0.02 = 98.778 g/mol ≅ 98.78 g/mol.
It means that you have to protect your hand.with gloves
Answer:
4
<h3>explanation:</h3>
Carbon has four valence electrons and here a valence of carbon is four.