Answer: 20 mg Te-99 remains after 12 hours.
Explanation: N(t) = N(0)*(1/2)^(t/t1/2)
N(t) = (80 mg)*(0.5)^(12/6)
N(t) = 20 mg remains after 12 hours
The penetrating power of alpha rays, beta rays, and gamma rays varies greatly. Alpha particles can be blocked by a few pieces of paper. Beta particles pass through paper but are stopped by aluminum foil. Gamma rays are the most difficult to stop and require concrete, lead, or other heavy shielding to block them.
Answer:
1249.88 mol.
Explanation:
∵ no. of moles of Fe = mass of Fe/atomic weight of Fe.
<em>∴ no. of moles of Fe </em>= (6.98 x 10⁴ g)/(55.845 g/mol) = <em>1249.88 mol.</em>
Answer:
A) measuring mass of metal used in a reaction
Explanation:
Quantitive observations is data involving statistics and numerical values.
Tollen's test is an organic test that determines whether the sample is an adehyde or not. When aldehydes are present, the reaction forms a silver compound which refers to the other name of Tollen's as silver mirror test. The aldehyde among the choices is C. pentanal