Conceptual Physics

C.9 In the sun, 4 hydrogen nuclei undergo a multi-step process and eventually form a helium-4 nucleus (plus some positrons,

neutrinos and gamma rays, all of negligible mass). What is this an example of?

i. Nuclear fission

ii. Nuclear fusion

iii. Alpha decay

iv. Chain reaction

C.10A radioactive sample emits both alpha particles and negative beta particles. If a uniform external magnetic field is present in

the region, what will be observed regarding the paths of the emitted particles?

i. Neither path bends.

ii. The paths of both particles bend in the same direction.

iii. Only one particle's path bends.

iv. The particles' paths bend in opposite directions.

Section Problems

Section 3 - Components of the nucleus

3.1 A neutral atom of potassium has 19 protons in its nucleus. How many electrons does it possess?

electrons

3.2 For the neutral chlorine atom , determine the (a) mass number, (b) number of protons, (c) number of neutrons (d)

number of electrons.

(a) is the mass number

(b) protons

(c) neutrons

(d) electrons

3.3 For a doubly-ionized calcium ion, which is a atom with two electrons removed (leaving it with a net charge of +2e),

determine the (a) mass number, (b) number of protons, (c) number of neutrons (d) number of electrons.

(a) is the mass number

(b) protons

(c) neutrons

(d) electrons

3.4 What is the mass of an electron, measured in atomic mass units?

u

Section 6 - Nuclear properties

6.1 In a Rutherford-like experiment that analyzes electrons that are scattered from a sample, a scientist measures the radius of a

nucleus in the sample to be 4.8×10í^15 m. What of these is likely to be the mass number of the nucleus?

i. 1

ii. 2

iii. 4

iv. 16

v. 64

6.2 Find the mass number of a nucleus whose radius is approximately one-half that of uranium-240.

Section 7 - Sample problem: nuclear density

7.1 Estimate the radius of a sphere of nuclear matter whose mass is equal to that of the Earth, 5.97×10^24 kg. Take 2.3×10^17

kg/m^3 as the density of nuclear matter.

m

(^718) Copyright 2000-2007 Kinetic Books Co. Chapter 38 Problems