Earth's surface is considered "young" because there are very few visible impact craters. describe at least three causes/processes responsible for earth having so few impact craters relative to the "older" surface of the moon, despite throughout geological history having been impacted at the same rate.

There are 6.022, 104 atoms of hg in 1 mole of hg the number of atoms in 45 moles of hg can be found by multiplying 4.5 by 6.022, 102 which is the number of atoms in 4.5 moles of hg, correctly written in scientific notation with the correct number of significant figures? 0 21,109 0 21,100 271, 1024 27.099, 100 mark this and retum save and exit submit

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.