<span>Halflife is the time needed for a radioactive molecule to decay half of its current mass. If t is the time elapsed, the formula for the halflife would be:
final mass= original mass * </span>

<span>
If you put the information of the problem into the formula, the equation will be:
</span>final mass= original mass *

final mass= 800g *
Answer:
1. Granite
2. 535.5J
Explanation:
1. The lower the specific heat capacity of a substance, which is the amount of heat needed to raise the temperature of a particular mass of substance by 1 °C or K, the slower the rate at which the temperature is raised.
In this question 1, the substance with the lowest specific heat capacity in J/gK is GRANITE, hence, it will raise temperature the slowest.
2. Using the formula as follows:
Q = m × c × ∆T
Where;
c = specific heat capacity
Q = amount of heat (J)
m = mass of substance
∆T = change in temperature (°C)
m = 35g, c = 0.45 J/g°C, ∆T = 54°C - 20°C = 34°C
Q = 35 × 0.45 × 34
Q = 535.5J
CaSO4. It has 6 atoms while Fe2O3 has 5 atoms
Explanation:
Fe2O3 contains 2 atoms of Iron(Fe) and 3 atoms of Oxygen(O) = 2 + 3 = 5 atoms
CaSO4 contains 1 atom of Calcium(Ca), 1 atom of Sulphur(S) and 4 atoms of Oxygen(O) = 1 + 1 + 4 = 6 atoms
Diphosphorus pentachloride