Explanation:
A cation is a positively charged ion.
An anion is a negatively charged ion.
- In a cation, electrons are usually lost
- In an anion, electrons are usually gained.
In an atom, the balance between the number of protons and electrons determine whether they become an anion or cation.
Protons are positively charged particles.
Electrons are negatively charged
When an atom gains electrons, the number of electrons becomes more than that of protons. This leaves a net negative charge on the atom and it makes an anion.
When an atom loses electrons, the number of protons becomes more than that of electrons. This leaves a net positive charge on the atom and makes a cation.
Two atoms of different elements that are chemically combined are called compounds.
Answer : The chemical formula of pure substances are different from those of mixtures because all the matter that exists on earth can be classified into two categories namely; pure substances and mixtures.
A pure substance always consists of a single element or compound. Example Oxygen is formed only of oxygen (O) atoms; whereas the table salt which is formed only by sodium chloride (NaCl) molecules is a compound which is made up of pure elements. A pure substance cannot be further divided into its components.
A mixture is made up of different compounds and/or elements. It can be easily separated using any physical method. Example, sand, salt and saw dust mixed together as a mixture. Also, it will not have a definite chemical formula.
Please refer the attachment for better understanding.
Molar solubility is the number of moles that are dissolved in 1 L solution.
when BaF₂ dissolves it dissociates into the following ions
BaF₂ --> Ba²⁺ + 2F⁻
if the molar solubility of BaF₂ is X, then molar solubility of Ba²⁺ is X and F⁻ is 2x
then the formula for the solubility product constant -ksp is;
ksp = [Ba²⁺][F⁻]²
ksp = X * (2X)²
ksp = 4X³
since ksp = 1.7 x 10⁻⁶
4X³ = 1.7 x 10⁻⁶
X = 0.0075 M
molar solubility of BaF₂ is 0.0075 M