Which of these substances are compounds? How do you know?

A. Salt (NaCl)

B. Nitrogen (N)

C. Helium (He)

D. Water (H2O)

Element 1 has 1 valence electron, element 2 has 2 valence electrons, element 3 has 3 valence electrons, element 4 has 4 valence electrons, which is the least reactive? A. Element 1 B. Element 2 C. Element D. Element 4

A primary source of hydrocarbons is:

Can Neon form any compounds?

What happens in reactions that take place under ideal conditions

Enter your answer in the provided box. in a 0.740 m solution, a weak acid is 12.5% dissociated. calculate ka of the acid.

Do pure substances have the same chemical and physical properties

How is matter conserved in a chemical reaction

Define Percent transmittance

Express (3 x 104) (4 x 1023) in scientific notation

The theoretical yield of aspirin in a reaction is 721 g. What is the percent yield if 461 g is produced?