Answer:
Zinc is Zn and Magnesium is Mg
Different isotopes of the same element must have a different mass number
Answer:
Yes, the investigations will reach similar conclusions about the reactivity of H2 and Cl2
Explanation:
1. The law of multiple proportions says that when elements form compounds, the proportions of the elements in those chemical compounds can be expressed in small whole number ratios. This means that regardless of whether 1000 times more of the products are used, the reactivity of the products is established by the chemical reaction
2. The law of multiple proportions is an extension of the law of definite composition, which states that compounds will consist of defined ratios of elements.
3. A reaction with more reactants will need more care because more products are produced, which can be toxic
4. H2 and Cl2 reactivity does not depend on the quantities but the chemical properties of each compound
Answer: a) 
acid : hydronium ion
base : methoxide ion
conjugate acid : methanol
conjugate base: water
b) 
acid : hydrogen chloride
base : ethoxide ion
conjugate acid : ethanol
conjugate base: chloride ion
c) 
acid : methanol
base : amide ion
conjugate acid : ammonia
conjugate base: methoxide ion
Explanation:
According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.
The species accepting a proton is considered as a base and after accepting a proton, it forms a conjugate acid.
The species losing a proton is considered as an acid and after loosing a proton, it forms a conjugate base
For the given chemical equation:
a) 
acid : hydronium ion
base : methoxide ion
conjugate acid : methanol
conjugate base: water
b) 
acid : hydrogen chloride
base : ethoxide ion
conjugate acid : ethanol
conjugate base: chloride ion
c) 
acid : methanol
base : amide ion
conjugate acid : ammonia
conjugate base: methoxide ion
.