What is the most abundant gas in Earth's present day atmosphere?

methane

oxygen

carbon dioxide

nitrogen

If a substance has a density of 2.82 g/mL, what will be the volume (in mL) of a 5.71 g sample

How is a cation different from a anion

How many covalent bonds are there in one molecule of silica, SiO2?

The electrons lost from the reaction center of photosystem i are replaced by electrons from ___.

what would be the effect on the properties of the water molecule if oxygen and hydrogen had equal electronegativity?

What are the first five elementsof the periodic table?

Name 3 characteristics that can be used to identify minerals

Hemoglobin, the oxygen-carrying protein in red blood cells, has four iron atoms per molecules ad contains 0.340 percent iron by mass. calculate the molar mass of hemoglobin

Nancy wants to find out how the steepness of a hill's slope affects the amount of soil that erodes from it. She has soil, a long pan, and a pile of books with which to build a model hillside. She has a watering can to model rainfall.

Elements on the periodic table are arranged by increasing?