What volume of a  0.100mhcl0.100mhcl  stock solution should be used to prepare  250.00ml250.00ml  of  0.0250mhcl0.0250mhcl?

62.5 mL

We are given;

We are required to calculate the Volume of the stalk solution.

We are going to use the dilution formula;

V₁ = M₂V₂ ÷ M₁

    = (0.025 M × 0.25 L) ÷ 0.100 M

    = 0.0625 L

But, 1 L = 1000 mL

V₁ = 62.5 mL

Therefore, the volume of the stock solution is 62.5 mL

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.