Name: Date:
Student Exploration: Half-life
Vocabulary: daughter atom, decay, Geiger counter, half-life, isotope, neutron, radiation,
radioactive, radiometric dating
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. Have you ever made microwave popcorn? If so, what do you hear while the popcorn is in
the microwave? I hear popping while I make popcorn.
2. If you turn the microwave on for two minutes, is the rate of popping always the same, or
does it change? Explain.
The rate of popping is not the same. When you first put the popcorn in there is not a lot of
popping, once the popcorn starts to get warm enough it starts to pop a lot, and once all the
popcorn seeds have been popped there is not a lot of popping anymore.
Gizmo Warm-up
Like an unpopped kernel in the microwave, a radioactive
atom can change at any time. Radioactive atoms change by
emitting radiation in the form of tiny particles and/or
energy. This process, called decay, causes the radioactive
atom to change into a stable daughter atom.
The Half-life Gizmo™ allows you to observe and measure
the decay of a radioactive substance. Be sure the sound is
turned on and click Play ( ).
1. What do you see and hear?
I hear a kind of popping, static kind of sound.
Note: The clicking sound you hear comes from a Geiger counter, an instrument that detects
the particles and energy emitted by decaying radioactive atoms.
2. What remains at the end of the decay process? Daughter atoms.
, 3. Is the rate of decay fastest at the beginning, middle, or end of the process? The rate of
decay is the fastest at the beginning.
Student Exploration: Half-life
Vocabulary: daughter atom, decay, Geiger counter, half-life, isotope, neutron, radiation,
radioactive, radiometric dating
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. Have you ever made microwave popcorn? If so, what do you hear while the popcorn is in
the microwave? I hear popping while I make popcorn.
2. If you turn the microwave on for two minutes, is the rate of popping always the same, or
does it change? Explain.
The rate of popping is not the same. When you first put the popcorn in there is not a lot of
popping, once the popcorn starts to get warm enough it starts to pop a lot, and once all the
popcorn seeds have been popped there is not a lot of popping anymore.
Gizmo Warm-up
Like an unpopped kernel in the microwave, a radioactive
atom can change at any time. Radioactive atoms change by
emitting radiation in the form of tiny particles and/or
energy. This process, called decay, causes the radioactive
atom to change into a stable daughter atom.
The Half-life Gizmo™ allows you to observe and measure
the decay of a radioactive substance. Be sure the sound is
turned on and click Play ( ).
1. What do you see and hear?
I hear a kind of popping, static kind of sound.
Note: The clicking sound you hear comes from a Geiger counter, an instrument that detects
the particles and energy emitted by decaying radioactive atoms.
2. What remains at the end of the decay process? Daughter atoms.
, 3. Is the rate of decay fastest at the beginning, middle, or end of the process? The rate of
decay is the fastest at the beginning.
