Which particles are found in an atom's nucleus?
AnswerProtons and neutrons
The nucleus holds protons and neutrons; electrons are outside it.
Science · Facts & stats
Nuclear facts & stats
7 fact-checked facts about nuclear science, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
What powers the Sun?
AnswerNuclear fusion
The Sun fuses hydrogen into helium in its core, releasing huge amounts of energy.
Going deeper
What is the half-life of a radioactive substance?
AnswerThe time for half of its atoms to decay
After one half-life, half of the original radioactive atoms have decayed.
An alpha particle is the same as the nucleus of which element?
AnswerHelium
An alpha particle has two protons and two neutrons, identical to a helium-4 nucleus.
In Einstein's equation E = mc squared, what does c stand for?
AnswerThe speed of light
E = mc squared shows that a small amount of mass equals a huge energy because c is so large.
Expert level
Chicago Pile-1, the first reactor to achieve a self-sustaining nuclear chain reaction in 1942, was led by whom?
AnswerEnrico Fermi
Enrico Fermi's team achieved the first self-sustaining chain reaction on December 2, 1942.
Who discovered the neutron in 1932?
AnswerJames Chadwick
James Chadwick proved the neutron's existence in 1932 and won the 1935 Nobel Prize in Physics.
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