Unit 2 Study Guide

o  Avogadro’s number can be defined as the number of particles in…

o  3 moles of calcium have a mass of…

o  A 54g sample of aluminum contains…

o  Calculate the mass in kilograms of 9.3 moles of O2.

o  A sample of lead contains 3.1x1023 atoms. Calculate the mass of the sample

o  In 1911 Rutherford conducted an experiment where he bombarded gold foil with

o  The results of his experiment lead him to believe…

o  Who was the first person to suggest the idea of an atom?

o  How did Rutherford’s gold foil experiment lead to the discovery of the proton?

o  Explain in full sentences, why Dalton’s atomic theory was incorrect

o  Most of the mass within the atom is contained in the

o  Isotopes are atoms with different;

o  Which part of the atom contains the most mass? Explain your answer fully.

o  The number of protons in one atom of an element determines the atom’s ______, and the number of electrons determines the ______of the element. The ______of an element is the total number of protons and neutrons in the ______of an atom.

Particle / Charge / Location / Mass
Species / Protons / Neutrons / Electrons
Se
29Si
He
O2-

o  Elements in the periodic table are arranged in order of increasing…

o  A family of elements that contains the most unreactive non- metals is …

o  Elements that lie along the zig- zag line are the …

o  Write the electronic configurations for the following atoms/ ions

Mg

S2-

o  Write the shortened electronic configuration for the following atoms

Sr

As

o  What is the empirical formula for a compound that is 26.56% K, 35.41% Cr, and 38.03% oxygen?

o  What is the formula of magnesium chlorate

o  An 240g sample of a radioisotope decayed to 30g after 24 days. What was the total mass of the original sample after 8 days?

o  What is the symbol for an beta particle?

o  Calculate the percentage by mass of zinc in zinc chloride.

o  Three isotopes of argon occur in nature, Ar- 36 (35.97amu, 0.445%), Ar- 38 (37.96amu, 0.089%), and Ar- 40 (39.969amu, 99.466%). Calculate the average atomic mass of argon.

o  Name the group of elements that have 7 valence electrons.

o  The empirical formula of a compound is CH. The experimental molar mass is 26.04g/mol. Determine the molecular formula of the compound.

o  Calculate the percentage by mass of oxygen in sulfuric acid, H2SO4

o  Calculate the percentage by mass of oxygen in laughing gas, N2O

o  Write the nuclear equation for the alpha decay of neptunium- 237

o  Write the nuclear equation for the beta decay of americium- 243

o  Write an equation showing the reaction between N- 15 and an alpha particle to produce a neutron and a new product.