Try to untie the knot from the balloon let some air out and tie if back....
Answer:
half lives passed=5
given sample=90g
sample left=2.8125g
Explanation:
no. of half lives=total time/half life
no.=19days/3.8days
no.=5 days
after 5 half lives sample left=2.8125g
Answer: 13 grams
Explanation:
The quantity of heat energy (Q) released from a heated substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Since,
Q = 202.8 Joules
Mass of silver = ?
C = 0.240 J/g °C.
Φ = 65°C
Then, Q = MCΦ
202.8J = M x 0.240 J/g °C x 65°C
202.8J = M x 15.6 J/g
M = (202.8J / 15.6 J/g)
M = 13 g
Thus, the mass of silver is 13 grams
