Chapter 4

Question 1

Matter

Answer 1

Anything with mass and volume.

Made of small particles.

Question 2

Atom

Answer 2

The basic unit of matter.

Question 3

What did Democritus believe?

Answer 3

Atoms are indivisible.

Question 4

What are the 4 parts to Dalton’s atomic theory?

Answer 4

1. Atoms are the basic unit of matter.
2. Atoms of the same element are identical, atoms of different elements are different.
3. Atoms of different elements can physically and chemically combine.
4. Chemical reactions occur when atoms are separated, joined, or rearranged. Atoms are never changed into other elements atoms as a result of chemical reactions

Question 5

Mixture

Answer 5

A physical blend of atoms.

Question 6

Compound

Answer 6

Chemically combining of particles.

Question 7

How can we observe atoms?

Answer 7

Using a scanning tunneling microscope.

Question 8

Is Dalton’s theory excepted?

Answer 8

Yes, except we know atoms are divisible.

Question 9

Electrons

Answer 9

Negative charge and outside the nucleus.

Question 10

Proton

Answer 10

Positive charge and inside the nucleus.

Question 11

Neutron

Answer 11

No charge, inside the nucleus.

Question 12

What did J.J. Thomas notice with magnets?

Answer 12

Opposites attract and the same repel.

Question 13

What did J.J. Thomas first call atoms?

Answer 13

Corpuscles

Question 14

What is the mass of an electron compared to a hydrogen atom?

Answer 14

1/1840 mass of a hydrogen atom.

Question 15

Quarks

Answer 15

Smaller particles that make up subatomic particles.

Question 16

Describe the “Plum Pudding” Model

Answer 16

In this model, the protons and neutrons were spread out in the atom.

Question 17

Atomic Nucleus

Answer 17

Contains protons and nuetrons.

Overall positive charge.

Question 18

Explain what happened to the alpha particles in Rutherford’s experiment?

Answer 18

1. Most passed straight through with slight deflections.
2. Some deflected at very large angles.
3. Very few bounced back.

Question 19

What is the atom mostly?

Answer 19

Empty space.

Question 20

Nuclear Atom

Answer 20

Protons and neutrons are in the nucleus.

Electrons are distributed around the nucleus and occupy most of the atom’s volume.

Question 21

Why are elements different?

Answer 21

They contain a different number of protons and neutrons.

Question 22

Atomic Number

Answer 22

The number of protons in the nucleus of an atom.

Question 23

Are protons and electrons equal?

Answer 23

Yes, in an electrically equal atom.

Question 24

Mass Number

Answer 24

Mass number= protons + nuetrons

Question 25

How else can the composition of an atom be represented?

Answer 25

Shorthand notation

Question 26

Shorthand Notation Formula

Answer 26

mass number (over) atomic number

Question 27

Isotopes

Answer 27

Atoms that have the same number of protons but a different number of neutrons.
This gives them a different mass number, but the same chemical behavior.

Question 28

Hydrogen-1

Answer 28

proton-1
electron-1
nuetron-0

Question 29

Hydrogen-2

Answer 29

proton-1
electron-1
nuetron-1

Question 30

Hydrogen-3

Answer 30

proton-1
electron-1
nuetron-2

Question 31

What is the atomic weight of an element?

Answer 31

A weighted average mass of an atom.

Question 32

How do you calculate the atomic weight of an element?

Answer 32

Multiply the mass of each isotope by its natural abundance, expressed in decimal, and then add the products.

Question 33

Periodic Table

Answer 33

An arrangement of elements in which elements are separated into groups based on a set of repeating patterns.

Question 34

How is the periodic table arranged?

Answer 34

In order of increasing atomic number.
Periods- 7 horizontal rows
Groups- verticle columns
Elements have similar chemical or physical properties.