U2L13 DE PS - Wed Oct 21 - Unit 2 Review

​U2L1 - Thu Sep 25 - 2.2 Discovery of Atomic Structure (and 2.1)

​​U2L1 - Thu Sep 25 - 2.2 Discovery of Atomic Structure (and 2.1)

• Atoms are made of the subatomic particles protons, neutrons and electrons. 

• Protons are positive and electrons are negative. 

• Electrons are very light and are on the outside of the atom.

• Protons and neutrons are heavy and are in a dense center called the nucleus.
  
  

​​U2L1 - Thu Sep 25 - 2.2 Discovery of Atomic Structure (and 2.1)

• It was the work of several scientists over many years to discover the structure of the atom

​​U2L1 - Thu Sep 25 - 2.2 Discovery of Atomic Structure (and 2.1)

• JJ Thomson worked with cathode ray tubes.

• Had a vacuum (nothing inside)

• Energizes pieces of metal w/ high voltage and they shoot out beams of electrons from cathode (-) to anode (+)

​​U2L1 - Thu Sep 25 - 2.2 Discovery of Atomic Structure (and 2.1)

• Milliken charged up oil drops with negative charge and measured the amount of charge they had by how fast they fell between charged plates

• Noticed it was always a multiple of the same number… that charge came in pieces (negative charge was quantized)

  → atoms give off negative charge in pieces (electrons)

​​U2L1 - Thu Sep 25 - 2.2 Discovery of Atomic Structure (and 2.1)

• Becquerel noticed that uranium gave off…. something. He knew that because it left photos behind.

• Curie built on his work and named the stuff coming out of atoms radiation and the process radioactivity - the spontaneous emission of energy and particles from atoms

​​U2L1 - Thu Sep 25 - 2.2 Discovery of Atomic Structure (and 2.1)

• Rutherford shot alpha radiation at thin pieces of gold foil and notice they scattered a certain way

• a way that only made sense if atoms were mostly empty but had small dense positive centers (nucleus)

Multiple Choice

Which particles make up the majority of an atom's volume but contribute almost nothing to its mass?

• Protons

• Neutrons

• Electrons

• Nuclei

Multiple Choice

Particles smaller than atoms that compose them are called:

• Molecules

• Subatomic particles

• Compounds

• Isotopes

Multiple Choice

When high voltage is applied to electrodes in a nearly empty glass tube, what type of radiation is produced?

• Alpha rays

• Cathode rays

• Gamma rays

• X-rays

Multiple Choice

Which subatomic particle was identified as the component of cathode rays?

• Proton

• Neutron

• Electron

• Positron

Multiple Choice

What term describes atoms that spontaneously emit radiation?

• Ionized

• Radioactive

• Isotopic

• Excited

Multiple Choice

According to Rutherford's model, where is almost all of an atom's mass located?

• Evenly distributed throughout the atom

• In the electron cloud

• In a tiny, dense nucleus

• In the outer shells

Multiple Choice

The nucleus of an atom is:

• Where most electrons are located

• The largest part of the atom

• small, dense region containing protons and neutrons

• Made only of neutrons

Multiple Choice

What fundamental property of matter did Millikan's oil drop experiment demonstrate?

• Mass is continuous

• Charge is quantized

• Atoms are indivisible

• Energy is conserved

U2L2 - Fri Sep 26 - 2.3 The Modern View of Atomic Structure

U2L4 - Wed 10/1 - Mass number redo

U2L2 - Fri Sep 26 - 2.3 The Modern View of Atomic Structure

• Atoms are made of the subatomic particles protons, neutrons and electrons.

• Protons are positive (+1 charge) and electrons are negative (-1 charge).

• Protons and Neutrons are heavy

U2L2 - Fri Sep 26 - 2.3 The Modern View of Atomic Structure

• Same charges near each other repel.

• What holds the protons together in the nucleus is a special force between protons and neutrons - the strong nuclear force

• Neutrons = glue of the nucleus

U2L2 - Fri Sep 26 - 2.3 The Modern View of Atomic Structure

• Atomic number of element = identity of element = number of protons

• Atoms are born neutral, with equal amounts of electrons and protons

• (though # electrons can change later)

• Atomic number = # protons = (if neutral) # electrons

U2L2 - Fri Sep 26 - 2.3 The Modern View of Atomic Structure

• Atom are born with a random amount of neutrons

• (usually close to # protons, some amounts more common)

• Same element, different # neutrons = isotopes

U2L2 - Fri Sep 26 - 2.3 The Modern View of Atomic Structure

• Mass number = # protons + # neutrons

• (isotopes have same atomic #, different mass #)

U2L4 - Wed 10/1 - Mass number redo

• Be able to interpret mass number and atomic number correctly

Multiple Choice

Which particle has a mass approximately 1836 times greater than an electron?

• Alpha particle

• Proton

• Photon

• Neutrino

Multiple Choice

A neutral atom has 19 protons. How many electrons does it have?

• 18

• 19

• 20

• 39

Multiple Choice

Which fundamental force overcomes the electromagnetic repulsion between protons in the nucleus?

• Weak nuclear force

• Strong nuclear force

• Gravitational force

• Van der Waals force

Multiple Choice

Two atoms have the same number of protons but different numbers of neutrons. What are they called?

• Isomers

• Allotropes

• Isotopes

• Ions

Multiple Choice

The atomic number of an element tells you the number of:

• Neutrons in the nucleus

• Protons in the nucleus

• Electrons in the ion

• Protons plus neutrons

Multiple Choice

In ¹⁴₆C, what do the numbers 14 and 6 represent?

• 14 = atomic number, 6 = mass number

• 14 = number of neutrons, 6 = number of protons

• 14 = mass number, 6 = atomic number

• 14 = number of protons, 6 = number of electrons

Multiple Choice

An atom of aluminum has 13 protons and 14 neutrons. Which is the correct notation for this atom?

• ¹⁴₁₃Al

• ²⁷₁₃Al

• ¹³₂₇Al

• ²⁷₁₄Al

U2L5 - Fri 10/3 - 2.5 Periodic Table

U2L5 - Fri 10/3 - 2.5 Periodic Table

• Periodic table arranges elements in order of increasing atomic number

• elements with similar chemical properties in same column

• Repeating patterns of properties

U2L5 - Fri 10/3 - 2.5 Periodic Table

• Rows = Periods

• Columns = Groups

  Group 1 and 2 also called 1A and 2A, Group 13 - 18 also called 3A - 8A

U2L5 - Fri 10/3 - 2.5 Periodic Table

• Rows = Periods

• Columns = Groups

  Group 1 and 2 also called 1A and 2A, Group 13 - 18 also called 3A - 8A

U2L5 - Fri 10/3 - 2.5 Periodic Table

• Elements in the same group have similar properties

U2L5 - Fri 10/3 - 2.5 Periodic Table

• A stepped line runs from boron (B) to astatine (At)

  Metals: left of the line (except H)

  Nonmetals: right of the line

  Metalloids: along the line

Multiple Choice

Which pair of elements would have the most similar chemical properties?

• N and O

• Mg and Al

• Cl and Br

• Li and He

Multiple Choice

The vertical columns of the periodic table are called _____ and the horizontal rows are called _____.

• Periods; groups

• Groups; periods

• Families; series

• Sections; categories

Multiple Choice

For the element phosphorus (P), identify its atomic number, group, and period:

• Atomic number = 31, Group = 3A, Period = 5

• Atomic number = 15, Group = 5A (15), Period = 3

• Atomic number = 15, Group = 3A, Period = 5

• Atomic number = 7, Group = 5A, Period = 2

Match

Match the following

• Silicon (Si)

• Sulfur (S)

• Sodium (Na)

Metalloid

Nonmetal

Metal

• Metalloid

• Nonmetal

• Metal

U2L7 - Wed 10/8 - 2.6 Molecules and Molecular Compounds

U2L7 - Wed 10/8 - 2.6 Molecules and Molecular Compounds

• molecules are groups of connected atoms.

• There are several ways of representing molecules

U2L7 - Wed 10/8 - 2.6 Molecules and Molecular Compounds

• Molecular formulas the amount and types of each atom

• Different letters = different elements

• Amount goes in subscript after

• Structural formulas show all atoms as letters and connections as lines

U2L7 - Wed 10/8 - 2.6 Molecules and Molecular Compounds

• Molecular formulas show the exact amounts of each atom in a molecule

• Empirical formulas show simplest whole-number ratios, relative amounts

U2L7 - Wed 10/8 - 2.6 Molecules and Molecular Compounds

• Molecular formulas show the exact amounts of each atom in a molecule

• Empirical formulas show simplest whole-number ratios, relative amounts

U2L7 - Wed 10/8 - 2.6 Molecules and Molecular Compounds

• Diatomic molecules have exactly 2 atoms bonded

Multiple Choice

What is the molecular formula for the compound shown in this ball-and-stick model?

• CO

• CO₂

• 2CO

• C₂O₂

Multiple Choice

Which structural formula represents the molecular formula NH₃?

Multiple Choice

Which of the following is a diatomic molecule?

• NH₃

• H₂

• CH₄

• H₂O

Multiple Choice

An empirical formula shows _____, while a molecular formula shows _____.

• Actual numbers of atoms; simplest whole-number ratio

• Simplest whole-number ratio; actual numbers of atoms

• How atoms are bonded; types of elements present

• Three-dimensional shape; how atoms are connected

U2L8 - Thu 10/9 - 2.7 Ions and Ionic Compounds

U2L8 - Thu 10/9 - 2.7 Ions and Ionic Compounds

• Ions are atom that have more protons or more electrons and they have a net charge (an excess of positive or negative charge)

• Ions form when atoms gain or lose electrons

U2L8 - Thu 10/9 - 2.7 Ions and Ionic Compounds

• Anions form by gaining electrons, are negative

• Cations form by losing electrons, are positive

U2L8 - Thu 10/9 - 2.7 Ions and Ionic Compounds

• Net charge has an amount and a charge

• Think of net charge as telling you whether an ion has more positive of negative charge and how much more

U2L8 - Thu 10/9 - 2.7 Ions and Ionic Compounds

• Net Charge calculated by subtracting : # protons - # electrons

U2L8 - Thu 10/9 - 2.7 Ions and Ionic Compounds

• Ionic compounds form by transferring electrons between atoms

• Get a bunch of oppositely charged ions stuck together because opposite charges attract

• Arrange themselves in a 3D repeating lattice

U2L8 - Thu 10/9 - 2.7 Ions and Ionic Compounds

• Ionic compounds usually form from a combination of a metal + nonmetal

• Quickest way to tell is by looking for presence of metal

Multiple Choice

What is formed when an atom gains or loses electrons?

• Isotope

• Ion

• Molecule

• Element

Multiple Choice

Which statement correctly describes ion formation?

• Cations form by gaining electrons; anions form by losing electrons

• Cations form by losing electrons; anions form by gaining electrons

• Both cations and anions form by gaining electrons

• Both cations and anions form by losing electrons

Multiple Choice

An atom has 17 protons and 18 electrons. What is its net charge?

• 1-

• 1+

• 35+

• 0 (neutral)

Multiple Choice

Which diagram best represents an ionic compound's structure?

Multiple Choice

Which compound contains ionic bonds?

• NH₃

• CO₂

• MgO

• N₂O

Multiple Choice

SO₄²⁻ is an example of:

• Monatomic ion

• Polyatomic ion

• Neutral molecule

• Element

U2L9 - Fri 10/9 - 2.8 Naming Inorganic Compounds Part 1
U2L11 - Thu 10/16 - 2.8 Naming Inorganic Compounds Part 2
U2L12 - Fri 10/17 - 2.8 Naming Inorganic Compounds Part 3

U2L9 -> U2L12 - 2.8 Naming Inorganic Compounds

• Positive ions just are just called by the name of the element and the word ion

• Single element negative ions drop end of element name, replace with -ide

U2L9 -> U2L12 - 2.8 Naming Inorganic Compounds

• In an ionic compound, the last element in the formula is a negative ion (anion)

U2L9 -> U2L12 - 2.8 Naming Inorganic Compounds

• Some polyatomic negative ions have special -ide names

U2L9 -> U2L12 - 2.8 Naming Inorganic Compounds

• Watch out for special groups

U2L9 -> U2L12 - 2.8 Naming Inorganic Compounds

• Anions (negative ions) where theres an element combined with oxygens are called oxyanions

• They have -ate and -ite names depending on how many oxygen

U2L9 -> U2L12 - 2.8 Naming Inorganic Compounds

• When naming ionic compounds with oxyanions, double check how many oxygens in the oxyanion and pick the right name

Multiple Choice

What is the name of the compound K₂S?

• Potassium sulfide

• Potassium sulfate

• Potassium sulfur

• Potassium sulfite

Multiple Choice

Ca(CN)₂ is named

• Calcium carbon nitride

• Calcium cyanide

• Calcium cyanate

• Calcium cyanite

Multiple Choice

What is the correct name for NaClO₄?

• Sodium chlorate

• Sodium perchlorate

• Sodium chlorite

• Sodium hypochlorite