Which of these pairs of elements have the same number of valence electrons? A. phosphorus (P) and chlorine (Cl) B. berylium (Be) and calcium (Ca) C. chlorine (Cl) and helium (He) D. oxygen (O) and carbon (C)

What is the potential energy of 4kg object sitting on a 3m ledge?

Calculate the [oh] for 0.46 Hcl

How many neutrons are found in Cr-54

A sample of gas occurs 9.0mL at a pressure of 500mmHg. A new volume of the same sample is at 750mmHg. Use two significant figures in answer on volume.

Liquid sodium is being considered as an engine coolant. How many grams of liquid sodium (minimum) are needed to absorb 1.00 MJ of energy (in the form of heat) if the temperature of the sodium is not to increase by more than 10.0 °C? Use CP = 30.

What is the mass in grams of 390 mL

Around 1910, Rutherford bombarded gold foil with alpha particles. Most of the alpha particles passed straight through. To his surprise, a smaller number were deflected by 180°. This summary recounts the scientific discovery of A.

What is the density? Mass = 120 g Volume = 96 mL

A spoonful of salt is stirred into a pot of water. The salt is a

What are some catchy projects titles for the question, "What liquids cause the most tooth decay?"