Question

Someone help explains these question pls x

Answer 1

1. Isotopes: the same element, the same atomic number, but different mass numbers

Atomic mass: the average atomic mass of all its isotopes

The mass of an atom of carbon-12= 12 amu ( atomic mass unit) because it has a stable nucleus

`\tt RAM~X=(the~average~mass~of~1~atom~X)/((1)/(12)* mass~of~atom~C-12 )`

So RAM relative to isotopes Carbon-12 (C)

2. Ionic Formula is formed from cation(positive charge) and anion(negative charge)

Cation : Na⁺ ( positively charged 1)

Anion : SO₄²⁻ (negatively charged 2)

The anion cation's charge is crossed , then the compound :

`\tt \boxed{\bold{Na_2SO_4}}`

3. pH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.

pH = - log [H⁺]

[H⁺] = 0.00001 M = 10⁻⁵ M

`\tt pH= -log 10^(-5)\\\\pH=5~log~10\\\\pH=\boxed{\bold{5}}`