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

a. Oxygen and BromineB) Carbon and LeadC) Oxygen and CarbonD) Sodium and Magnesium

1. A pyrotechnician mixes 280 g of black powder for a firework. Find the amount of oxygen, carbon dioxide, and sulfur dioxide generated when this firework bursts, if the oxidizing agent in the powder is saltpeter. 2.

Which sample has more atoms in it? 150.0 g of gold or 10.0 g of lithium.

The compound 1,2 - dibromopropane could be formed from the reaction of

The diffrent names for the diffrent ways the moon can look from earth or blank?

Within one period, which group has the lowest first ionization energy? A) alkaline earth metals B) noble gases C) alkali metals D) halogens E) carbon family

What is the specific heat capacity of a 17.5g sample of an unknown metal that releases 6700J of heat when it cools from 90 to 25 degrees C?

How can equilibrium of a closed system chemical reaction be disturbed? Select all that apply. Adding or removing products or reactants. Keeping the concentration of products and reactants the same. Keeping the temperature of the system constant.

Why does an exothermic reaction need activation energy?

The temperature of 15 grams of water increases by 3.0 degress. how much heat was absorbed by water?

What are the four types of stoichiometry problems?