<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.
A = mass number, A = protons + neutrons
Z = atomic number, Z = protons
neutrons = A - Z
neutrons = 18 - 8 = 10
Answer:
The stronger conjugate base will be the weaker acid; i.e., the acid with the smaller Ka-value.
Explanation:
Given conjugate base CN⁻ => weak acid => HCN => Ka =4.9 x 10⁻¹⁰
Given conjugate base OCN⁻ => weak acid=> HOCN => Ka = 3.5 x 10⁻⁴
Ka(HCN) << Ka(HOCN) => CN⁻ is a much stronger conjugate base than OCN⁻
1, 2, and 3
hope it helps next time upload with picture
Explanation :
The balanced chemical reaction will be,

By the stiochiometry, 3 moles of solid copper(II)oxide react with 2 moles of ammonia gas to give 3 moles of copper metal, 1 mole of nitrogen gas and 3 moles of liquid water.
The states of matter of each elements and compound is,
Copper(II)oxide is in solid state
Ammonia is in gaseous state
Copper metal is in solid state
Nitrogen is in gaseous state
Water is in liquid state