Answer:

Definition:
Half-life- The time taken for half of the radioactive isotopes to decay.
Explanation:
How does radioactive decay work? Radioactive decay is a process by which unstable nuclei become more stable through the emission of alpha or beta particles or gamma rays.
Since a half-life is the time taken for half of the isotopes to decay, we can simply divide the initial mass of 100 grams by 2; this gives us 50 grams.
1) Divide 100g by 2.

Answer:
True
Explanation:
The Sun rotates in the counterclockwise (CCW) direction when seen from its north pole. Since, the planets revolve around the Sun because of its gravity, the revolution of all the planets and their moons as seen from the north of the Sun is in CCW direction.
In fact most of the solar system bodies rotate in the same direction that is CCW. Some major exceptions to this are Venus and Uranus.
Almost all the planets and moons were made from the planetary disk around the Sun. Thus, they lie nearly in the same plane.
Answer:
Greatest gravitational energy is at "C".
The planet has to do work "against" the field to get to "C".
Also, if m v R (angular momentum) is constant then as R increases v must decrease for this term to be constant and KE = 1/2 M v^2 must decrease also to get to point C.
The gravitational acceleration of a planet is proportional to the planet's mass, and inversely proportional to square of the planet's radius.
So when you stand on the surface of this particular planet, you feel a force of gravity that is
(1/2) / (3²)
of the force that you feel on the surface of the Earth.
That's <em>(1/18)</em> as much as on Earth.
The acceleration of gravity there would be about <em>0.545 m/s²</em>.
This is about 12% less than the gravity on Pluto.
Answer:
I THINK IT'S <em>D.</em><em>.</em><em>.</em><em>.</em>
<em>HOPE </em><em>SO</em>