Answer:

Explanation:
-The chemical formula for Molybdenum (V) Dichromate is 
-There are 21 moles of oxygen per one mole of Molybdenum (V) Dichromate
-We apply Avogadro's constant to find the number of atoms of oxygen:

Hence, there are
Explanation:
100 CM = 1 m
45 CM = 45 / 100 = 0.45 m
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Answer: 6.12 kg
Explanation:
Since Mass of ball = ? (let the unknown value be Z)
Acceleration due to gravity, g= 9.8m/s^2
Height, h = 1.5 metres
Gravitational potential energy GPE = 90J
Gravitational potential energy depends on the weight of the ball, the action of gravity and height.
Thus, GPE = Mass m x Acceleration due to gravity g x Height h
90J = Z x 9.8m/s^2 x 1.5m
90 = Z x 14.7
Z = 90/14.7
Z = 6.12 kg
Thus, the bowling ball weigh 6.12 kilograms
Answer:
C. Fe: 24 electrons
Explanation:
From the analogy given, the atom with a charge of +2 is Fe having 24 electrons.
To calculate the charges on an atom;
Number of charges = Number of protons - Number of electrons.
O: 10 electrons: 8 protons = 8 - 10 = -2
N: 10 electrons; 7 protons = 7 - 10 = -3
Cl: 18 electrons; 17 protons = 17 - 18 = -1
So;
Fe: 24 electrons and 26 protons = 26 -24 = +2
Therefore, the solution is Fe