Answer:
This question is incomplete, however, the unknown compound can be inferred to be "Lithium Bromide"
Explanation:
The unknown compound firstly is said to be an ionic compound. An ionic/electrovalent compound is a compound in which it's constituent ions transfer/receive electron(s). They are mostly made of group 1 and group 7 elements. Examples include NaCl, NaF, LiF and KCl.
Also, the ion (metallic ion) that produces a red flame test colour in a flame test is the <u>Lithium ion (Li⁺).</u> Also, when dissolved in water or hexane, the only halogen that produces a red/orange colour is bromine. Hence, the unknown ionic compound can be inferred to be Lithium Bromide.
According to law of conservation of mass.
In a chemical reaction Mass is neither created nor destroyed.
- Mass of product =Mass of reactant
#1
Mass of water

#2
Mass of sulphur:-

Answer:
A and C represent elements while B and D represent Compounds
Explanation:
chemical elements cannot be broken down into simpler substances by any chemical reaction. While A chemical compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds
conduction - the transfer of heat to an object through contact
Answer: Law of conservation of mass explains these observations.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products formed must be equal to the mass of reactants taken.
In order to get the same mass on both sides, the atoms of each element must be balanced on both sides of the chemical equation.

Mass of reactants= mass of Mg+ mass of
= 48 g + 32 g = 80 g
Mass of products = mass of
= 80 g
Thus mass of reactants is equal to mass of products, thus law of conservation of mass is obeyed.