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

A. Salt (NaCl)

B. Nitrogen (N)

C. Helium (He)

D. Water (H2O)

An ice cube melts and then the liquid water evaporates. Which statement is true about the mass of water that goes through each change of state?

The molecules in a sample of oxygen gas are in constant motion. What does an increase in temperature indicate about the movement of the molecules? A. The molecules are moving closer together. B. The molecules are moving farther apart. C.

What is impossible to do with a hypothesis? O A. You cannot disprove it. O B. You cannot prove it true. O C. You cannot test it. D. You cannot gather enough evidence to determine if it is true or false.

When the following redox equation is balanced with the smallest whole number coefficients, what is the coefficient of Sb3 + (aq) ? BrO3 - (aq) + Sb3 + (aq) → Br - (aq) + Sb5 + (aq) (acidic solution)

In order for a solute to dissolve in a solvent, what must be true?

What does the number next to the ion signify?

Write a molecular equation for the precipitation reaction potassium chloride and lead (II) acetate

Which outcome is not caused by gravitational force?

Explain the properties of the substance around us depend on the atoms and molecules that compose them

What is an ion (1 mark) what is the charge on a chloride ion (1 mark) what is an ionic bond (1 mark)