IB Chemistry SL Unit 2

232/92 U -> 4/2 He + 228/90 Th What form of decay is this?

Alpha

Put the types of Radiation in order by their penetration power (weakest to strongest)

Alpha, Beta, Gamma

130/52 Te -> 0/-1 e + 130/53 I What form of decay is this?

Beta

Beta emission is associated with - a. conversion of a neutron to a proton. b. conversion of a proton to a neutron. c. increase in mass number. d. decrease in mass number by 4 and atomic number by 2. e. emission of γ rays.

D

Nuclear Model

Discovered that the atom was mostly empty space and that the positive charge was at the center of the atom in a space called the nucleus, and that the electrons orbited it.

Quantum Model

Discovered that the electrons don't move in orbits, but rather waves and that electrons aren't on a straight path, but in cloud orbits. Most commonly accepted model.

Planetary Model

Discovered that the electrons stabely orbited around the Nucleus in levels.

In a Neutral Isotope, what is the number of Electrons, Protons and Neutrons in Niobium-93?

Electrons - 41 Protons - 41 Neutrons - 52

Electrons (Charge, Mass, Location)

Electrons have a -1 negative charge and are located in the electron cloud. They have a mass so small it's equivalent to 0.

Solid Sphere Model

First model of the atomic model. Came up with the idea that atoms are indivisible and that atoms of one element differ from atoms of other elements.

Do Non Metals tend to gain or lose electrons during chemical reactions?

Gain electrons.

Periodic Table (What is it and how is it arranged?)

It is a collection of all elements, ordered by their atomic number.

Average Atomic Mass

It is the average atomic mass of all isotopes by their abundance. Ex - Atomic Mass of Lithium is 6.941

Do Metals tend to gain or lose electrons during chemical reactions?

Lose electrons

Which of these are Metals? Iodine, Bromine, Helium, Neon, Argon, Krypton, Magnesium, Sulfur

Magnesium

What are the properties of Metalloids?

Metalloids are more ductile and malleable than Non Metals, but less than Metals. They are not that shiny, but also not fully dull.

What are properties of Metals?

Metals are ductile, malleable and can conduct heat and electricity. They are also shiny.

Neutrons (Charge, Mass, Location)

Neutrons have a neutral charge and are located in the nucleus. They have an atomic mass of 1.

What are properties of Non Metals?

Nonmetals are not ductile or malleable and cannot conduct heat or electricity well. They are dull.

What is the product isotope when Thorium - 234 decays by Beta Decay?

Prolactinium-234

Protons (Charge, Mass, Location)

Protons have a +1 positive charge and are located in the nucleus. They have an atomic mass of 1.

What is the Modern Atomic Model we accept today?

Quantum Model

Put each Model in Order Solid Sphere, Nuclear, Planetary, Quantum, Plum Pudding

Solid Sphere Plum Pudding Nuclear Planetary Quantum

Which of these are Non Metals? Lithium, Sodium, Calcium, Sulfur, Magnesium, Barium, Lead, Indium, Bismuth, Iron, Copper, Zinc, Nickel

Sulfur

Which of these are Metalloids? Iodine, Bromine, Helium, Tellurium, Neon, Argon, Krypton, Sulfur, Phosphorous

Tellurium

What is the Atomic Mass of this element? What is the Atomic Number?

The Atomic Mass is 14 The Atomic Number is 6

If the Isotope of this Silver-97, what is it's Atomic Mass?

The Atomic Mass is 97

Half-Life

The amount of time it takes for an element to lose half of its original mass.

Alpha Decay

The decay of a Helium-4 atom from an unstable element. The weakest form of radioactivity and cannot go through paper.

Beta Decay

The decay of an electron caused by the seperation of a Neutron into a proton and an electron.

Gamma Decay

The decay of energy from an unstable atom. Usually an extra of another decay, is not released by itself.

Atomic Number

The number of Protons in an atom. Ex - Atomic Number of He is 2

Mass Number

The number of protons and neutrons or the isotope number. Ex - Isotope-8 Mass Number - 8

Radioactive Decay

The process an unstable atom goes through to remove energy or mass.

Where are Metalloids located? (blocks)

They are located at the staircase between Metals and Non-Metals. Located in blocks S and P

Where are Metals located?

They are located on the left of the Metalloid staircase. Located in blocks S, P, D and F.

Where are Non Metals located?

They are located on the right of the Metalloid Staircase. Located in block P.

Do Metalloids tend to gain or lose electrons during chemical reactions?

They often gain or lose electrons, depending on who they pair with.

Plum Pudding Model

This model was the first one with Electrons that were scattered along a cloud of positive charge.

Isotope

Two of the same elements but with a varying number of Neutrons. Ex - Carbon - 12: 6 protons 6 neutrons Carbon - 13: 6 protons 7 neutrons

35/16 S -> X + 35/17 Cl Find X

X = 0/-1 e

184/74 W -> 4/2 He + X Find X

X = 180/72 Hf

208/84 Po → 204/82 Pb + X What form of Decay is X?

X = 4/2 He Alpha Decay

138/x Ba → 138/57 La + 0/−1 e Find the value of X here.

X = 56

After 24.0 days, 2.00 milligrams of an original 128.0 milligram sample remain. How many half-lives must have elaspsed to get to 0.015625 remaining?

n = 6

After 24.0 days, 2.00 milligrams of an original 128.0 milligram sample remain. What is the half-life of the sample?

0.015625 half live

What is the number of Neutrons in each Isotope?

1. 3 2. 4 3. 5

Pd-100 has a half-life of 3.6 days. If one had 6.02 x 1023 atoms at the start, how many atoms would be present after 20.0 days?

1.28 x 1022 atoms remain

What is Atomic Mass of this element?

12.0

The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed?

12.5 g remaining

What percentage of an original polonium sample will remain after three half-lives have passed?

12.5% will remain

A sample of Cesium is 75% Cs-133, 20% Cs-132, and 5% Cs-134. What is the average atomic mass?

132.85 Amu

What is the atomic mass of nitrogen? (Use Periodic Table)

14.0067

100.0 grams of an isotope with a half-life of 36.0 hours is present at time zero. How much time will have elapsed when 5.00 grams remains?

155.6 hours

Write a balanced Alpha Decay Equation for 234/94 Pu

234/94 Pu -> 4/2 He + 230/92 U

Write a balanced Beta Decay Equation for 45/20 Ca

45/20 Ca -> 0/-1 e + 45/21 Sc

What is the Atomic Number of this element?

47

Calculate the Average Atomic Mass of Lithium, which occurs as two isotopes. 6.017 Amu occurs at 7.30% frequency while 7.018 Amu occurs at 92.70% frequency.

6.94 Amu

What is the number of Protons in this element?

7

Os-182 has a half-life of 21.5 hours. How many grams of a 10.0 gram sample would have decayed after exactly three half-lives?

8.75 g have decayed