What is the name of the group of elements that are human-made and do not occur in nature?

What are the two phases of a waxing moon

Which radio wave technologies would be unaffected by satellites that are not working properly? A. space communication and television broadcasting B. television broadcasting and GPS C. MRI and radio telescopes D.

the steel bed of a suspension bridge is 200m long at 20 C. If the extremes of temperature to which it might be exposed are - 30 C to 40 C, how much will it contract and expand

1. According to the nebular theory, the solar system formed from? A. accretion of protoplanets. B. a large, thin cloud of dust and gas. C. colliding planetesimals. D. all of the above 2.

Suppose two comets, comet A and comet B, were orbiting the Sun, having the same average orbital radii. If comet A had a higher eccentricity than comet B, which comet would, during some portion of its orbit, have the highest orbital speed?

What is the concentration of H + ions at a pH = 7?

Suppose that Paul D. Trigger fires a bullet from a gun. Will the speed of the bullet leaving the muzzle will be the same as the speed of the recoiling gun? Explain.

A certain rock contains large jagged pieces of other rocks cemented by fine particles what type of rock is this explain

Could a nucleus that has one proton but no neutrons exist?

Which physical quantities has the unit kg·m·s-1?