The formula for specific gravity is:

where
is the density of the substance and
is the density of water.
The density of water,
= 
Substituting the values in above formula we get,


The formula of density is:

The density of mercury is 
The mass of mercury is 
Substituting the values in density formula:


Answer:
Intermolecular bonds are found in all of them. They can come in different versions.
3) Answer is: because elements have different emmision spectrum.
Emission spectrum of a chemical element is the spectrum of frequencies emitted due to an atom making a transition from a high energy state to a lower energy state. Each element's emission spectrum is unique.
4) Answer is: lithium chloride and sodium chloride do not have similar colors.
Lithium ion has red and sodium ion has yellow emission spectrum.
5) Answer is: because metals have valence electrons in different energy shells.
Each transition has a specific energy difference.
6) Answer is: salts of alkaline and earth alkaline metals.
For example barium chloride gives green light.
Answer:
31
Explanation:
In order for an atom to have a neutral charge, it needs to have the same number of protons and electrons. You can see by the illustration that the atomic number is 31, so this element has 31 protons. Knowing that, we also know that it must have 31 electrons to be neutral.