Helium (He) has the lowest melting point of <span>-272.2 °C.</span>
<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.
Answer:
Odd answer choices, but I would put "It shows you that water is a reversible reaction, which contains hydrogen and hydroxide reactions."
Explanation:
The first choice is weird, although water can be written as HOH that doesn't help you understand acids and bases.
The third choice doesn't do that either, and there are more ways for water to be formed than that.
The second choice helps you understand acids and bases, specifically, in water's self-ionization process. It also shows you that it is neutral because it is formed from Hydrogen, which is usually present in acids, and a Hydroxide group, which is usually present in bases.