Answer: B) metals, non-metals, metalloids
An example of a metal is iron. A non-metal example is oxygen, which is a gas at STP (standard temperature and pressure).
A metalloid is a bit of a mix between a metal and non-metal element. It's sorta like an element that has both properties of metals and non-metals, or it's in a murky gray area. An example of a metalloid would be silicon.
Answer:
Make nitrous oxide or laughing gas by heating ammonium nitrate and collecting the vapor by bubbling it up into a container over water. ... It's easy to make nitrous oxide or laughing gas at home or in the lab. All you need is a heat source and ammonium nitrate
Explanation:
Answer: 1. C. polar covalent: electrons shared between silicon and sulfur but attracted more to the sulfur
2. B) 
3. B) Fluorine
Explanation:
1. A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.
Electronegativity difference = electronegativity of sulphur- electronegativity of silicon = 2.5 -1.8 = 0.7
Thus as electronegativity difference is less than 1.7 , the cond is polar covalent and as electronegativity of sulphur is more , the electrons will be more towards sulphur.
2. A molecular compound is usually composed of two or more nonmetal elements. Example:
Ionic compound is formed by the transfer of electrons from metals to non metals. Example:
,
and 
3. For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here K is having an oxidation state of +1 and as the compound formed is KZ, the oxidation state of non metallic element Z should be -1. Thus the element Z is flourine which exists as diatomic gas 
Answer:
The heat from the Earth's cores radioactive process makes the lithospheric plates move sometimes away or toward each other.
Hope it helps :)