Answer: low pressure
Explanation: Air at the equator is warmer and the air above expands, becomes less dense and rises
Answer: Hydrogen that is not used in balloons because hydrogen burns very easily.
pls mark brainliest
Answer: compound
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: Copper
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: water
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present. Example: Air
The first reaction is a synthesis reaction (A+B -> AB)