Which two elements have the same number of valence electrons?

Na and Sr

Zr and H

O and S

Mg and P

Planetesimals are made from A. Rock B. Gas C. Stars D. Clouds

Sulfur molecules exist under various conditions as S2, S, S4, S6, and S8. Which of the following statements are true? a) The number of sulfur atoms in one mole of each of these molecules is the same.

Which substance is an electrolyte? (1) CCl4 (3) HCl (2) C2H6 (4) H2O

Why is it important to use a reaction with a high atom economy?

You observe that the snow pile on your yard has decreased in size although the temperature has not been above freezing since the last snowfall what most likely occurred

The molecules of a substance are moving rapidly in a container. The molecules do not interact with each other. If the container is opened, the molecules will escape from the container.

Why is fluorine a gas?

What is the empirical formula for a compound if a sample contains 3.72g of p and 21.28g of cl?-pcl5-pcl3-p2cl10-p2cl5

Use the equation 2HgO--> 2Hg+O2 to find how many moles of mercury are produced if 27 g of oxygen are produced. 2.1 1.3 2.6 2.4

How much mass does an electron, proton, and neutron have?