When we have this balanced equation for a reaction:
Fe(OH)2(s) ↔ Fe+2 + 2OH-
when Fe(OH)2 give 1 mole of Fe+2 & 2 mol of OH-
so we can assume [Fe+2] = X and [OH-] = 2 X
when Ksp = [Fe+2][OH-]^2
and have Ksp = 4.87x10^-17
[Fe+2]= X
[OH-] = 2X
so by substitution
4.87x10^-17 = X*(2X)^2
∴X^3 = 4.8x10^-17 / 4
∴the molar solubility X = 2.3x10^-6 M
The answer is B. This is because Sodium has 1 valence electron and Fluorine has 7 valence electrons. All elements want 8 valence electrons so they may be stale, like the noble gases are. Hope this helps.
The answer is Solid.
This is on account of the substances that develop a solid are packed in a settled, firmly pressed geometric plan.
Answer:The earths plates shifting
Explanation: The movement releases stored-up 'elastic strain' energy in the form of seismic waves, which propagate through the Earth and cause the ground surface to shake.
Answer:
<em>Protons:
</em>
- Positively charged particle
- The number of these is the atomic number
- All atoms of a given element have the same number of these
<em>Neutrons: </em>
- Isotopes of a given element differ in the number of these
- The mass number is the number of these added to the number of protons
Explanation:
Protons (<em>positively charged</em>), neutrons (<em>neutral</em>) and electrons (negatively charged) are smaller than an atom and they are the main subatomic particles. The nucleus of an atom is composed of protons and neutrons, and the electrons are in the periphery at unknown pathways.
The <em>Atomic number</em> (Z) indicates the number of protons (
) in the nucleus. Every atom of an element have the <em>same atomic number</em>, thus the <em>same number of protons</em>.
The <em>mass number </em>(A) is the sum of the <em>number of protons</em> (
) <em>and neutrons</em> (N) that are present in the nucleus: <em>A= Z + N</em>
<em>Isotopes</em> are atoms of the <em>same element </em>which nucleus have the <em>same atomic number</em> (Z), and <em>different mass number (A)</em>, it means the <em>same number of protons</em> (
) and a <em>different number of neutrons</em> (N). For example, the oxygen in its natural state is a mixture of isotopes:
99.8% atoms with A= 16, Z=8, and N=8
0.037% atoms with A=17, Z=8, and N=9
0.204% atoms with A=18, Z=8, and N=10