Answer:
Both are equal
Explanation:
Mass of starting material i.e Aluminium is
grams
The weight of oxygen is 
There are 4 atoms of aluminium and 3 atoms of oxygen
Thus, the total mass of starting material is
mass of one atom of aluminium
mass of one atom of oxygen

grams
Mass of new substance is also equal to
mass of one atom of aluminium
mass of one atom of oxygen

grams
Answer:
C.
The pan will be the same temperature as the stove.
Explanation:
Answer: According to the BBC, the internationally recognized death toll shows that 31 died as an immediate result of Chernobyl. Two workers died at the site of the explosion, another died in hospital soon after due to their injuries and 28 operators and firemen are believed to have died within three months of the accident.
Explanation:
Answer is: 0,0095 mol of hydrogen gas will be produced in reaction.
Chemical reaction: Ca + 2HCl → CaCl₂ + H₂.
m(Ca) = 0,38 g.
n(H₂) = ?
n(Ca) = m(Ca) ÷ M(Ca).
n(Ca) = 0,38 g ÷ 40 g/mol
n(Ca) = 0,0095 mol.
from reaction: n(Ca) : n(H₂) = 1 : 1.
n(H₂) = n(Ca) = 0,0095 mol.
n - amount of substance.