RADIOACTIVE DECAY Exercise 2

Section 25.2 Radioactive Decay Practice Test

	1.	If a thorium-230 atom undergoes alpha decay, what are the products of the reaction?

		a.	actinium and an alpha particle
		b.	actinium and a positron
		c.	radium and an alpha particle
		d.	radium and a positron

	2.	What ratio is used to evaluate the stability of a nucleus?

		a.	the electron to proton ratio
		b.	the neutron to proton ratio
		c.	the electron to neutron ratio
		d.	the atomic number to mass number ratio

	3.	What conditions in the nucleus usually result in beta decay?

		a.	The nucleus has too many neutrons.
		b.	The nucleus has too many protons.
		c.	The valence electrons are lost.
		d.	The atomic mass is greater than 300 amu.

	4.	What happens during positron emission?

		a.	A proton is converted into a neutron and a positron.
		b.	A neutron is converted into a proton and a positron.
		c.	A proton is converted into a neutron and an electron.
		d.	An atomic explosion occurs.

	5.	What happens to the mass of an atom when it undergoes alpha decay?

		a.	There is no change in mass.
		b.	The mass decreases by 1.
		c.	The mass increases by 4.
		d.	The mass decreases by 4.