In chemistry the need for standards when measuring quantities are in place for accurate measurement that is recognized world wide. This way, no matter what language people use, they will always understand there standards.
Answer: 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here iron is having an oxidation state of +3 called as 
cation and oxide 
is an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral 
.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
D. Making the reactant particles larger
Answer:
Explanation:
meiosis
Haploid sperm and eggs are produced via meiosis.
Answer:
1.41 × 10⁻¹⁰ M
Explanation:
We have a solution with a pH of 9.85 at 25 °C. We can calculate the concentration of H⁺ using the following expression.
pH = -log [H⁺]
[H⁺] = antilog -pH
[H⁺] = antilog -9.85
[H⁺] = 1.41 × 10⁻¹⁰ M
H⁺ is usually associated with water molecules forming hydronium ions.
H⁺ + H₂O → H₃O⁺
Then, the concentration of H₃O⁺ ions is 1.41 × 10⁻¹⁰ M.
