Once you identify the compound as Ionic<span>, </span>Molecular, or an Acid, follow the individual ... chemicalformulas<span>, write </span>whether<span> the compound is </span>ionic or molecular<span>, and ...</span>
Reaction:

Magnesium is a stronger reducing agent than copper and is thus able to reduce copper(II) oxide.
Products of the reaction: Magnesium oxide and metallic copper.
I think the right answer for this question is option A. The energy absorbed so the mass will be increased.
The law of conservation of mass dictates that the total mass of reactants must be equal to the total mass of the products. Thus:
mass(MgO) = mass(Mg) + mass(O)
mass(MgO) = 24 + 16
mass(MgO) = 40 g
The third option is correct.
Answer:
helium=1,2atm
argon=2,8atm
Explanation:
partial is pressure exerted by each gas in a system since 30% is helium it means 70% is argon
argon =70%x4
helium=30%4