Answer:
True
Explanation:
I did the test and got 100
a. They are both normally found as gases in the atmosphere. TRUE
That is correct, the oxygen and nitrogen are found in large quantities in the air around us.
b. They can be either liquids or gases. TRUE
Under certain temperatures any gas will transform into a liquid.
c.They turn from gas to liquid at the same temperature. FALSE
Oxygen it will pass into a liquid at -183 °C while nitrogen pass into a liquid at -195.8 °C.
d.They can be changed from gases to liquids by heating them. FALSE
The gases change to liquids by cooling them.
The correct answer for the following questions that are presented above are these ones:
(1) b. Pressure. The <span>physical effect can change the boiling point of a substance is the pressure.
(2) </span><span>Evaporation only occurs at the surface of a liquid. TRUE.</span><span>
(3) </span>d. freezing. The change from liquid to solid, or the reverse of melting, is called freezing.
Answer : The formula unit of Sr & Cl is 
and the formula unit of Al & S is 
Explanation :
Formula unit : it is defined as the lowest number ratio of ions of an elements in an ionic compound or covalent compound.
For the formula unit of Sr & Cl, two chloride ions
are needed to neutralize the one strontium ion
.
For the formula unit of Al & S, three sulfide ions
are needed to neutralize the two aluminium ion
.
The formula unit of and are shown below.
