Potassium-40 (40k) is a radioactive isotope of potassium (atomic number 19). how many neutrons are located in the nucleus of potassium-40?

If 26.2 grams of a pure compound contain 8.77 * 1022 molecules, what is the molecular weight of this compound? Answer in units of g/mol.

How does chemical weathering keep the Earth from getting too hot to support life?

A 15.0 kg chunk of ice falls off the top of an iceberg. If the chunk of ice falls 8.00m to to the surface of the water, what is the kinetic energy of the chunk of ice when it hits the water, and what is its velocity

Give the number of significant figures indicated. 0.066 0312

During a 4 hour trip, a boat sailed 70 km in 2 h. Then the boat did not move for 1 hour and traveled 26 km in the last hour. What was the boat's average speed?

A salt crystal has a mass of 0.18 mg. how many nacl formula units does it contain?

Which of the following is easist to accelerate? A. bowling ball B. tennis ball C. golf ball D. ping pong ball

Fish need at least 4 ppm dissolved o2 for survival. part a what is this concentration in mol/l?

How does a runoff get polluted.

Anatom that has lewer neutrons than protons and more electrons than protons is