Chapter 2: Terms

Question 1

Magnitude of the charge of the electron

Answer 1

1.602x10^-19

Question 2

Atomic mass rule (1 amu = ?)

Answer 2

1.66054x10^(-24) grams

Question 3

How large is an angstrom?

Answer 3

1A=1-5.0 x 10^-10 meters

Question 4

Periodic Table: How are elements of similar properties arranged?

Answer 4

In columns

Question 5

Periodic Table: What are the elements in a horizontal row referred to as?

Answer 5

A “period”

Question 6

Which side of the Periodic Table (PT) do the metallic elements dominate?

Answer 6

The left and middle of the table

Question 7

Where are nonmetallic metals located on the PT?

Answer 7

Upper right side

Question 8

What is a diatomic molecule?

Answer 8

A molecule that contains two atoms

Question 9

What charges are cat- and anions?

Answer 9

Cation = +
Anion = -

Question 10

What are ionic compounds?

Answer 10

Electrically neutral, containing both anion and cation, being both metallic and nonmetallic.

Question 11

What are polyatomic molecules?

Answer 11

Atoms that are joined together, as in a molecule, but carry a net charge

Question 12

What is the mass of a proton?

Answer 12

1.0073 amu

Question 13

What is the mass of a neutron?

Answer 13

1.0087 amu

Question 14

What is the mass of an electron?

Answer 14

5.486 x 10^(-4)

Question 15

Dalton’s Atomic Theory

Answer 15

1. Elements are made of extremely small particles called atoms.
2. Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.
3. Atoms cannot be subdivided, created, or destroyed.
4. Atoms of different elements combine in simple whole-number ratios to form chemical compounds.
5. In chemical reactions, atoms are combined, separated, or rearranged.

Question 16

Electromagnetic Forces

Answer 16

Electrons are bound by electromagnetic wave mechanics into orbitals around atomic nuclei to form atoms, which are the building blocks of molecules. This governs the processes involved in chemistry, which arise from interactions between the electrons of neighboring atoms, which are in turn determined by the interaction between electromagnetic force and the momentum of the electrons.

Question 17

Define Strong Nuclear Forces

Answer 17

The force that binds protons and neutrons (nucleons) together to form the nucleus of an atom. On the smaller scale (less than about 0.8 fm, the radius of a nucleon), it is the force (carried by gluons) that holds quarks together to form protons, neutrons, and other hadron particles.

Question 18

Millikan Oil Drop Experiment

Answer 18

1. Watched droplets of oil fall due to gravity (mass was determined)
2. The oil drops were irradiated with X-rays and, as a result, became charged.
3. When the electrical force on the charged drops balanced the gravity force, then oil drops were suspended from air.

Derived Information

1. Charge of the electron: 1.602x10^(-19) coulombs
2. Mass of electron: 9.10x10^(-28)g

Question 19

Rutherford’s Gold Foil Experiment

Answer 19

Rutherford’s experiment consisted of a beam of alpha particles, generated by the radioactive decay of radium, directed normally onto a sheet of very thin gold foil in an evacuated chamber. A zinc sulfide screen at the focus of a microscope was used as a detector; the screen and microscope could be swiveled around the foil to observe particles deflected at any given angle. Under the prevailing plum pudding model, the alpha particles should all have been deflected by, at most, a few degrees; measuring the pattern of scattered particles was expected to provide information about the distribution of charge within the atom. However, the actual results surprised Rutherford. Although many of the alpha particles did pass through as expected, many others were deflected at small angles while others were reflected back to the alpha source. They observed that a very small percentage of particles were deflected through angles much larger than 90 degrees.

Derived:
Protons

Question 20

J.J. Thomson

Answer 20

Plum pudding model of atoms

Question 21

James Chadwick

Answer 21

Discovered protons

Question 22

Heterogeneous Mixture

Answer 22

a mixture where the components of the mixture Are not uniform or have localized regions with different properties.

rocks, oil and water, soup, pizza

Question 23

Homogeneous Mixture

Answer 23

a mixture where the components that make up the mixture are uniformly distributed throughout the mixture.

air, blood, saturated sugar water

Question 24

JJ Thomson’s Cathode Ray Experiment

Answer 24

“As the cathode rays carry a charge of negative electricity, are deflected by an electrostatic force as if they were negatively electrified, and are acted on by a magnetic force in just the way in which this force would act on a negatively electrified body moving along the path of these rays, I can see no escape from the conclusion that they are charges of negative electricity carried by particles of matter.”

-Thomson

Question 25

Ionic Compound

Answer 25

• Solid-state structure, forming a crystalline structure called a “lattice.”
• Because of this, they are very hard
• In their solid state, they do not conduct electricity.
• When melted in an aqueous solution, they act as strong electrolytes and conduct electricity.
• Are soluble in water, and insoluble in non-polar liquids and organic compounds.

Question 26

Molecular Compounds

Answer 26

• Usually exist in the liquid or gaseous state at standard temperature and pressure. This is because of a weak force of attraction between the atoms forming covalent bonds.
• Due to a weak force of attraction between the atoms, these compounds usually have a low melting and boiling point.
• The solid forms of molecular compounds are generally very soft and brittle. The covalent bonds in such compounds are flexible, and bend or break easily.
• Usually, molecular compounds are insoluble in water, but are soluble in organic solvents.