Answer:
The mass number is defined as the total number of protons and neutrons in an atom.
Explanation:
Answer:25,06 kJ of energy must be added to a 75 g block of ice.
ΔHfusion(H₂O) = 6,01 kJ/mol.
T(H₂O) = 0°C.
m(H₂O) = 75 g.
n(H₂O) = m(H₂O) ÷ M(H₂O).
n(H₂O) = 75 g ÷ 18 g/mol.
n(H₂O) = 4,17 mol.
Q = ΔHfusion(H₂O) · n(H₂O)
Q = 6,01 kJ/mol · 4,17 mol
Q = 25,06 kJ.
Explanation:
The balanced equation is 2HgO --> 2Hg + O2
Answer : The time passed in years is 
Explanation :
Half-life of carbon-14 = 5730 years
First we have to calculate the rate constant, we use the formula :



Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = initial amount of the reactant disintegrate = 15.3
a - x = amount left after decay process = 14.8
Now put all the given values in above equation, we get


Therefore, the time passed in years is 
When converted to a household measurement, 9 kilograms is approximately equal to a