<h2>Hardness, lustre, and colour.</h2>
Explanation:
These Rocks shown in photographs are made of different types of minerals which have properties as follows:
●The color of the rock is grey, brown and yellow after it is ground into a powder its color is streak.
● The lustre of the rock tells how shiny the rocks are.
● Other properties include hardness, texture, shape, and size.
An acid can be defined as a proton donor.
Answer:
Chemical reactions are balanced by adding coefficients so that the number of atoms of each element is the same on both sides. Stoichiometry describes the relationship between the amounts of reactants and products in a reaction.
Explanation: