Ions that are made of more than one atom are examples of

a. polyatomic ions.

b. negative ions.

c. positive ions.

d. neutral ions.

What hypothesis states that the continents were once joined to form a single supercontinent? A. continental drift B. paleomagnetism C. plate tectonics D. sea-floor spreading

238 U 92 is an isotope notation. what is the atomic number, mass number, number of protons, and number of neutrons?

A reaction produced 37.5 L of oxygen gas at 307 K and 1.25 atm. How many moles of oxygen were produced?

As the elements in Period 2 of the Periodic Table are considered in succession from left to right, there is a decrease in atomic radius with increasing atomic number. This may best be explained by the fact that the A.

7) change 21.1 mg into grams

When a chemical reaction takes place, the number of atoms of each element in the reactants

A scientist is measuring the pressure that is exerted by each of the following gases in the atmosphere: carbon dioxide, oxygen, and nitrogen. Which term most likely describes what she is measuring?

How would you expect energy to change during a chemical reaction? A. Energy will be increased. B. Energy will be decreased. C. Energy will be converted into another form. D. Energy will be consumed.

In the formula for the compound xcl4 the x could represent

What is the main function of antibodies? A: "Remembering" the characteristics of germs that have invaded your body in the past B: Creating new white blood cells C: binding themselves to invading antigens D:Signaling your immune system that antigens