There are 30 protons and 39 neutrons in the nucleus.
This must me the isotope of an element with an atomic mass close to 69 u.
The only candidates are Zn and Ga.
Zn has a zinc-69 isotope with mass 68.926 u.
Ga has a gallium -69 isotope with mass 68.925 u.
The isotope is probably

.
It has 30 protons and 39 neutrons.
Answer:
B. CA, 14
Explanation:
Atoms of elements contain small particles known as electrons, neutrons, and protons. The nucleus of an atom is made up of neutrons and protons which are at the center of the atom. Electrons on the other hand surrounds the nucleus. Electron has negative charge while proton has a positive charge. The number of neutrons is equivalent to the number of protons . In addition, the number of protons is equal to mass number minus the number of electrons.
For the compound
, it can be broken down into
and
. Its ion has a mass of 34 and 18 electrons which means it has already lost 2 electrons.
Therefore:
For the given element, the number of electrons is 18+2 = 20 electrons.
The number of protons = 34 - 20 = 14.
And the number of neutrons is 14.
Only option B has the correct answer.
Answer:

Explanation:
Your nuclear equation is

The main point to remember in balancing nuclear equations is that
- the sum of the superscripts and must be the same on each side of the equation.
- the sum of the subscripts must be the same on each side of the equation.
Then
85 = 0 + y, so y = 85 - 0 = 0
35 = -1 + x, so x = 35 + 1 = 36
The nucleus with atomic number 36 and atomic mass 85 is krypton-85.
The nuclear equation becomes

Answer:
e) pH is independent of concentration.
Explanation:
a) It is a mixture of a weak acid and its conjugate base. <em>TRUE. </em>A buffer is defined as a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid.
b) Resists pH changes because it reacts with added acid or base. <em>TRUE. </em>Thermodynamically, the reaction of added acid or base is faster with the buffer mixture than with H⁺ or OH⁻ ions of the solutions.
c) The maximum buffer capacity is at pH = pKa. <em>TRUE. </em>The buffer capacity is pka±1. For this, buffer capacity is maximum in pka.
d) pH is dependent on the solution ionic strength and temperature. <em>TRUE.</em> Ionic strength and temperature are factors that influence concentrations of ions in solutions as the H⁺ ion that is the responsible
e) pH is independent of concentration. <em>FALSE. </em>pH in a buffer depends completely of concentrations of the acid and its conjugate base or vice versa.
I hope it helps!