A. Air expands, becomes less dense and rises when the temperature is high due to the increased kinetic energy. This causes the air molecules to move around much more so they are further apart.
Answer:
They both have the same number of atoms
Explanation:
The number that indicates the amount of particles in a compound is the Avogadro's number (NA).
It does not matter the mass of compound we have, If we have 1 mol we will be sure that we are talking about 6.02×10²³ particles
6.02×10²³ represents the amount of atoms in twelve grams of 12-pure carbon and it is considered a reference to measure the amount of all kinds of substances present in a given system.
Answer:
The process where substance react with oxygen is called combustion.
Explanation:
When substance react with oxygen combustion is occur. The substance which burned is called fuel and in this process large amount of heat is released to the surrounding. It is exothermic process.
For example:
4Li + O₂ → 2Li₂O
2Mg + O₂ → 2MgO
S + O₂ → SO₂
The product which is formed as a result of combustion reaction are called oxides.
In given examples we can see that lithium, magnesium and sulfur react with oxygen and product formed is oxides of respective elements such as lithium oxide ( Li₂O), magnesium oxide (MgO) and sulfur oxide ( SO₂ ).
1 is D - double-replacements do not make solid metals
2 is A - to have complete combustion the original compound must ONLY have C, H and O
3 is B - the elemental Mg replaces the H in the HCl
Answer:
the density of CO2 gas at STP is 1.96 g/l.
