Concentrated hydrochloric acid is 12.0 M. What volume of this concentrated solution would be needed to mix with water to produce 100. mL of 5.0 M. (Hint: the
number of moles in the diluted solution must be the same as the number of moles
from the concentrated solution.)

41.67 ml HCl

Explanation:

n = M x V

Since the number of moles is the same:

M1 x V1 = M2 x V2

V1 = M2 x V2 /M1 =(0.1 L x 5.0 M) / 12.0 M = 0.041667 L = 41.67 ml

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.

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.