D) Radioactive contamination
Answer: 4Kcal
Explanation:
H= mcø
M=200g
C= 1 cal/g/°c
Ø= 40-20=20°c
H= 200*1*20= 4000calories= 4Kcal
1 mole ----------- 6.02 x 10²³ atoms
? mole ---------- 24.08 x 10²³ atoms
moles B = ( 24.08 x 10²³) x 1 / 6.02 x 10²³
moles B = 24.08 x 10²³ / 6.02 x 10²³
= 4 moles
Answer B
hope this helps!
