
If the half-life of a sample of a radioactive substance is 30 seconds, how much would be left after 60 seconds? <span>
A. one-fourth</span>
Answer:
Explanation:
2 Na+ 2 H2O → 2 NaOH + 1 H2
Cell theory was discovered from the scientist
Answer:
Explanation:
mass of the solution = volume x density = 200 x 1 = 200 gm
heat absorbed = m x s x Δ t , s is specific heat , Δt is rise in temperature
= 200 x 4.18 x ( 31.3 - 24.6 )
= 5601 J .
This is the enthalpy change required.