Question

1.Describe what happens to a carbon-11 atom when it undergoes positron emission.

The decay of a carbon-11 atom _____(options;changes a nuetron into proton, changes proton into neutron, is hit with a neutron, reconfigures its protons and neutrons) and this causes it to emit______(options; a negatively charged electron sized particle, a positively charged electron sized partticle, two atoms and several neutrons, two neutrons and two protons)

2.An atom undergoes radioactive decay according to this equation:

___ $mimetex?\fs3%20\;+\;_{2}^{4}\textrm{He}$ .

What is the identity of the resulting atom?

209, Bi →

A. $mimetex?\fs3%20_{\:\:81}^{205}\textrm{TI$

B. $mimetex?\fs3%20_{\:\:85}^{213}\textrm{At$

C. $mimetex?\fs3%20_{\:\:81}^{204}\textrm{TI$

D. $mimetex?\fs3%20_{\:\:85}^{210}\textrm{At$

3.Which statements correctly describe the decay rates of radioactive isotopes? choose ALL that apply

It takes two half-lives for a sample to fully decay.

The exact time when an individual atom will decay can be accurately predicted.

After each half-life, the amount of radioactive material is reduced by half.

All radioactive isotopes have the same half-life.

The decay of individual atoms in a sample of radioactive material is random.

4.What is the quantity of carbon-14 in a bone after 17,190 years if the initial mass of C-14 is 0.300 grams and the half-life is 5,730 years?

A.0.038 g

B.0.093 g

C.0.281 g

D.0.412 g

Answer 1

1/changes a proton into neutron

And a positively charged electron sized particle.

2/ A

3/The decay of individual atoms in a sample of radioactive material is random.

4/A. 0.038g

1/changes a proton into neutron And a positively charged electron sized particle. 2/A 3/The decay of individual atoms in a sample of radioactive material is random. /A. 0.038g When carbon 11 atom undergoes position emission, the decay of carbon - 11 atom charges a proton into and this cases it to exit a positively charged electron sized particle. An atom undergoes decay according to this equation: The identity of the resulting atom is The statement which correctly describe the decay rates of radioactive is the decay of individual atoms in a sample of radioactive material is random. The quartile of carbon - 14 is a bone 17,190 years if the mass of c - 14 is 0.300 and the half - left is 5730 years is 0.033 g. Explanation After each half left period the amount of carbon - 14 decay radioactivity by half. therefore we have After 1 half life: 50 x After 2