
Ore is a deposit in Earth's crust of one or more valuable minerals. The most valuable ore deposits contain metals crucial to industry and trade, like copper, gold, and iron. Copper ore is mined for a variety of industrial uses. Copper, an excellent conductor of electricity, is used as electrical wire.
<span>Which of the following lists characteristics of a lake and NOT a reservoir A. Artificial dam, fresh water B. natural dam, filled by runoff C. earth dam, salt water D. filled by erosion, cement dam
Answer is B: natural dam,filled by runoff</span>
Answer:
(a) the mass of the water is 3704 g
(b) the mass of the water is 199, 285.7 g
Explanation:
Given;
Quantity of heat, H= 8.37 x 10⁶ J
Part (a) mass of water (as sweat) need to evaporate to cool that person off
Latent heat of vaporization of water, Lvap. = 2.26 x 10⁶ J/kg
H = m x Lvap.

mass in gram ⇒ 3.704 kg x 1000g = 3704 g
Part (b) quantity of water raised from 25.0 °C to 35.0 °C by 8.37 x 10⁶ J
specific heat capacity of water, C, 4200 J/kg.°C
H = mcΔθ
where;
Δθ is the change in temperature = 35 - 25 = 10°C

mass in gram ⇒ 199.2857 kg x 1000 g = 199285.7 g
Molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.
While Atoms are single neutral particles,
Molecules are neutral particles made of two or more atoms bonded together.
Exaplmes for molecules
H2O (water)
N2 (nitrogen)
O3 (ozone)
CaO (calcium oxide)
C6H12O6 (glucose, a type of sugar)
NaCl (table salt
And examples for atoms
Neon (Ne)
Hydrogen (H)
Argon (Ar)
Iron (Fe)
Calcium (Ca)
Deuterium, an isotope of hydrogen that has one proton and one neutron.
Plutonium (Pu)
F-, a fluorine anion.