21.Which of the following are types of subatomic particles? a. nucleus
b. electrons
c. atoms
d. a&b

NO ITS NOT A!!
A nucleus contains two types of subatomic particles protons and neutrons.
A THIRD TYPE OF SUBATOMIC PARTICLE ARE ELECTRONS!
so the answer will be B. Electrons

The soviet union beat the us to the first successful launch, with the october 4, 1957, orbiting of sputnik 1, and later beat the us to have the first human in earth orbit, yuri gagarin, on april 12, 1961. the "race" peaked with the july 20, 1969, us landing of the first humans on the moon with apollo 11

The principle of independent assortment describee how different genes independently separate from one another when reproductive cells develop.