What two elements comprise most of a nebula? question 5 options: hydrogen and helium hydrogen and nitrogen oxygen and hydrogen carbon and hydrogen helium and lithium?

Which of the following elements would be the most reactive? a. iodine b. silicon c. silver d. argon

In a far-off galaxy, an astronomer observes a moon orbiting a planet. The moon stays in orbit because of the planet's gravity.

The equation below shows the decomposition of lead nitrate. How many grams of oxygen are produced when 11.5 g NO2 is formed? 2Pb (NO3) 2 (s) - - > 2PbO (s) + 4NO2 (g) + O2 (g

A Se ion has a mass number of 76 and a charge of - 2. Determine the number of neutrons, protons, and electrons in this ion.

A 75 gram bar of gold is cut into three equal pieces. How does the density of each piece compare to the density of the original bar? 1. Each piece is 1/3 the density of the original bar 2. Each piece is the same as the density of the original bar

What is the element 3O2 name

Why sulphur used for food preservation?

How would a solution that is labeled 5.0 molar be similar to one labeled 5.0 molal?

Calculate the percentage by mass of nitrogen in ptcl2 (nh3) 2.

Below are the structures of three fatty acids, palmitic acid, stearic acid, and oleic acid. what combination of these fatty acids could you use to make a fat that is liquid at room temperature?