8) The planet Mars, our moon, and Halley's comet all
A)
reflect the sun's light.
B)
are older than the earth.
C)
have highly elliptical orbits.
D)
were formed from collisions with the earth.
I NEED HELP WITH THIS PLS

Identify one disadvantage to each of the following models of electron configuration: -dot structures -arrow and line diagrams -written electron configurations type in your answer below. (answer) -dot structures do not show the distribution of electrons in orbitals and take up a lot of space. -arrow and line diagrams take up a lot of space and make it difficult to count electrons. -written configurations make it easy to lose count of electrons and do not show the distribution of electrons in orbitals.

What is the percent by mass of magnesium sulfate in mgso4.7h2o

You have a sample of a metal, the sample is exactly 6.02 x 1023atom, if the sample has a mass 55.85 what metal is your sample made of?