Answer: (3) silicon
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Silicon (Si)
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: ethane 
, propanone 
and water 
The particle that adds mass but no charge to the atomic nucleus is the neutron.
The nucleus contains both protons and neutrons.
Protons and neutrons have about the same mass.
However, protons have a positive charge, while <em>neutrons have no charge</em>,
Sodium Chloride, also known as table salt
Answer:
Ksp= 7.98 × 10^-13
Explanation:
According to the question, we are to calculate the solubility constant (Ksp) of Zinc carbonate (ZnCO3) in a dissolved solution.
The equilibrium of the reaction is:
ZnCO3 (aq) ⇌ Zn2+ (aq) + CO32- (aq)
According to this; 1 mole of Zinc carbonate (ZnCO3) dissolves to give 1 mole of Zinc ion (Zn2+) and 1 mole of carbonate ion (CO32-).
This illustrates that:
(Zn2+) = 1.12 x 10-4 g/L
(CO32-) = 1.12 x 10-4 g/L
However, 1.12 x 10-4 g/L is the solubility in mass concentration of ZnCO3, we need to convert it to molar concentration in mol/L by dividing by the relative molar mass of ZnCO3.
To calculate the molar mass of ZnCO3, we say:
Zn (65.4) + C (12) + 03 (16×3)
= 65.4+12+48
= 125.4g/mol.
Hence, molar concentration= 1.12 x 10-4 g/L / 125.4 g/mol
= 8.93 × 10^-7 mol/L.
Therefore;
Zn2+) = 8.93 x 10-7 mol/L
(CO32-) = 8.93 x 10-7 mol/L
Ksp = [Zn2+] [CO32-]
Ksp = (8.93 x 10-7) × (8.93 x 10-7)
Ksp = 7.98 × 10^-13
The statement which best described the effect of color on energy absorption and reflection is this: LIGHT COLORS REFLECT MORE AND ABSORB LESS THAN DARK COLORS. Black color absorbs all incident radiations while white color reflects all incident radiations; all other colors fall in the midst of these two colors.
