Answer: must have THE SAME number of atoms for each element
Explanation: Chemical equations must be balanced -- they must have the same number of atoms of each element on both sides of the equation. As a result, the mass of the reactants must be equal to the mass of the products of the reaction.
<span>density is how much matter is packed into one area. so the higher density the more likely it is to be heavier. for example, cork has a very low density and iron has a higher density.</span>
Answer:
a
Explanation:
it would be the most reasonable
Explanation:
because in the right side there is 2 hydrogen( H) and 2 chloride (Cl) to balace them we have to replace 2.
Answer: 72 grams of
are needed to completely burn 19.7 g 
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number
of particles.
To calculate the number of moles, we use the equation:

Putting in the values we get:


According to stoichiometry:
1 mole of
requires 5 moles of oxygen
0.45 moles of
require=
moles of oxygen
Mass of 
72 grams of
are needed to completely burn 19.7 g 