Answer:
Vapour pressure of a liquid varies with temperature
Explanation:
The vapour pressure of any liquid is directly proportional to the temperature of the liquid. This implies that, as the temperature of the liquid increases, the vapour pressure increases likewise and vice versa.
Since the vapour pressure of liquid varies with the temperature of the liquid, it is essential to know the water temperature in the experiment to determine the vapour pressure of water.
Answer:A+B - AB
Element a reaction with element b to create the newest element ab
Answer:
D
Explanation:
According to this question, each model of molecules in the options contains spheres of different colors and sizes representing different types of atoms. The atoms of the same element are the spheres of same color and size while atoms of different element are of different color or size.
Therefore, the model showing a molecule of a substance that is made up of three elements is model D because it is made up of three distinct spheres representing atoms of each element.
- The red sphere is the atom of the first element
- The big dark sphere is the atom of the second element
- The small white sphere is the atom of the third element
Answer: (3) silicon
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Silicon (Si)
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: ethane 
, propanone 
and water 
