Which of these pairs of elements have the same number of valence electrons

phosphorus (P) and chlorine (Cl)

beryllium (Be) and calcium (Ca)

chlorine (Cl) and helium (He)

oxygen (O) and carbon (C)

g A mass spectrum. The peak at mass 100 has a 8% relative abundance. THe peak with mass 85 has a 40% abundance. The peak at 71 has a 3% abundance. The peak at 57 has a 30% abundance. The peak at mass 43 has a 100% abundance.

Calculate the hydronium ion concentration and the pH when 50.0mL of 0.40M NH3 is mixed with 50.0 mL of 0.40M HCl. Showthe equation for the reaction in terms of the hydronium ion.

What obstacles does this sea turtle face once it is in the ocean?

What pressure is exerted by 932.3 g of CH4 in a 0.560 L steel container at 136.2 K?

Which set of compounds would form a buffer in aqueous solution? drag each item to the appropriate bin. hints?

The capacity of an eye dropper would be a few a kilometers be leiters C deciliters d milliluters

2C 2 H 6 + 7O 2 * **>4CO 2 + 6H 2 O if 7.0 g of C 2 H 6 react with 18 g of O 2, how many grams of water will be produced

22 days converted into how many seconds?

How do you do percent composition in chemistry?

Which mixture has the largest particle size?