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)

Suppose you are given a sample of a homogeneous liquid what would you do to determine whether it is a solution or a pure substance

What must be the specific heat of a sample of an unknown material of 36.359g, when 59.912J of heat are applied raising the temperature 152°C?

What is the difference between the number of electrons in an atom of selenium?

identify the terms, like terms, coefficients and constants 2+3a+9a

One way to make a supersaturated solution is to make a saturated solution and then a. dissolve more solute in it. b. click on a disk inside the solution. c. lower the temperature of the solution. d. raise the temperature of the solution.

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?

Condension occurs in the inside of your windows in Winters, why?

How can you use Hess's law to determine a reaction's enthalpy?

7. How much energy in KJ is released when 15.0 g of steam at 100.0 degrees Celsius is condensed and then frozen to ice at 0.0 degrees Celsius?