What is the mass number of an atom that contains 19 protons, 19 electrons, and 20 neutrons?

What molecules can be used for long-term energy storage?

A sample of gas contains 6.25 * 10-3 mol in a 500.0 mL flask at 265°C. What is the pressure of the gas in kilopascals? Which variables are given?

Amy is in a car moving quickly toward a stationary siren. Just as Amy moves past the siren, she notices a change in the _of the siren.

Identify the neutral element represented by this excited-state electron configuration, then write the ground-state electron configuration for that elemen

How many milliliters of a 1:5000 w/v solution of the preservative benzalkonium chloride can be made from 125 mL of a 0.2% w/v solution of the preservative? a. 1250 mL b. 2500 mL C. 625 mL d. 1875 ml

Consider the circuit 9.012 9.012 What is its equivalent resistance? Answer in units of 12.

out of 2.00 50 mL of water is added to 30 mL of a 0.50 M salt solution. What is the new concentration? (To write your answer using scientific notation use 1.0E-1 instead of 1.0 x 10-1)

If one object has more mass than another then it weighs more or less than the other object?

What is most believed by most scientists about the age of our solar system.

The water level in a graduated cylinder stands at 20.0 ml before and at 26.2 ml after a 16.74 g metal sample is lowered into the cylinder. what is the density of the sample. what metal is the sample most likely to be