Why does the mass number for an element differ from the average atomic mass for the element?

What is the mass number of beryllium with 5 neutrons

What is the lewis structure for the anion - CH2CN?

What causes effervescence?

What are two human activities that are harmful to birds?

Which statement must be true for any chemical reaction at equilibrium? (1) The concentration of the products is greater than the concentration of the reactants. (2) The concentration of the products is less than the concentration of the reactants.

Which is the balanced chemical equation showing hydrogen peroxide (h2o2) decomposing into hydrogen (h2) and oxygen (o2) ? 1. h2 + o2 → h2o2 2. 2 h2o2 → 2 h2 + o2 3. h2o2 → h2 + o2 4. 2 h2 + o2 → 2 h2o2?

Assuming constant pressure, rank these reactions from most energy released by the system to most energy absorbed by the system, based on the following descriptions: A. Surroundings get colder and the system decreases in volume. B.

Zircon is a mineral with the empirical formula ZrSiO4. If all the zirconium is 90Zr, all the silicon is 28Si, and all the oxygen is 16O, what mass of oxygen is present in 10. g of zircon?

Which property below is not a general property of metals: A. Ductile C. Malleable B. Poor conductor of heat D. High luster

Calculate the number of particles (atoms or molecules) of the following: 1. How many molecules are there in 24 grams of FeF3? 2. How many molecules are there in 450 grams of Na2SO4? 3. How many grams are there in 2.3 x 1024 atoms of silver?