The answer is b. radon-222. The alpha decay means that it will emit an alpha particle when decays. The alpha particle has two protons and two neutrons. So Radium(88) minus two protons will become Radon(86). And the atomic mass will become 226-4=222.
The answer to this question would be the second option or B (The moon's orbit is closer to Earth.) because there are multiple different high tides that are caused by either the moon being unusually close to the Earth or the moon is at it's Quarterly or New Moon phases.
Hope that this helped you! :D
The sun of the protons a D neutrons in the nucleus of an atom is called the ATOMIC MASS
The semi will have the hardest time changing direction because of its mass. The more mass there is, the more effort it takes to accelerate and decelerate as well as change direction.
Oxygen - element
Water - compound
Ocean - liquid solutions
Air - gaseous solution
Cloud - colloid
