Chap 3

Question 1

The four key features of Dalton’s atomic theory

Answer 1

• Elements are made of tiny, indivisible particles called atoms
• Atoms combine/can join together in whole number ratios (to form compounds).
• Atoms of each element are unique
• Atoms are unchanged in chemical reactions.

Question 2

The atom is

Answer 2

The fundamental unit of matter.
Each element is composed of a different type of atom, which gives each element its unique properties.
(‘atom’ derived from ‘atomos’, meaning: “indivisible”)

Question 3

The Law of Conservation of Mass (Antoine Lavoisier, born 1794)

Answer 3

States: “In chemical reactions, matter is neither created nor destroyed”

Question 4

The three foundational ideas:

Answer 4

• All mater is composed of atoms
• The atoms of each element have unique characteristics and properties
• -In chemical reactions. atoms are not changed, but combine in whole number ratios to form compounds.

Question 5

Can we see atoms?

Answer 5

No. Atoms are too small to be seen with a naked eye, or even a microscope.
Scientists use x-ray crystallography to visualize the arrangement of atoms.

Question 6

The Periodic table arrangement

Answer 6

Rows(horizontal)- called “periods”

Columns(vertical)- called “groups” or “families”

Question 7

Main group elements locations

Answer 7

The two side blocks (Columns 1A-2A (1&2) and 3A-8A(13-18))

Question 8

Location of the transition & inner transition elements

Answer 8

Block between the main group elements blocks (columns 3-12)

Question 9

Subatomic particles

Answer 9

Particles that make up atoms

Question 10

Location of Alkali Metals

Answer 10

Collum 1A

Question 11

Location of Alkaline earth metals

Answer 11

Collum 2A

Question 12

Location of Halogens

Answer 12

Collum 7A

Question 13

Location of Noble Gasses

Answer 13

Collum 8A

Question 14

Mass number =

Answer 14

protons + neutrons

Question 15

Atomic Theory

Answer 15

a theory describing matter in terms of fundamental units, atoms

Question 16

Atomic mass unit (u or amu)

Answer 16

A unit of mass equal to 1.66x10^-27kg

Question 17

Charge

Answer 17

a characteristic property of subatomic particles that affects how particles interact with each other

Question 18

Electron

Answer 18

A negatively charged sub-atomic particle. the electrons occupy the space around the nucleus.

Question 19

Nucleus

Answer 19

The tiny, dense center of an atom. The nucleus contains protons and neutrons.

Question 20

Electron cloud

Answer 20

the space around the nucleus. Accounts for nearly the entire volume of the atom

Question 21

Atomic number

Answer 21

The number of protons in an atom, also the number of electrons in a neutral atom

Question 22

What are six evens in uncovering atomic structure?

Answer 22

1) Volta’s electrochemical cell
2) Dalton’s atomic theory
3) Mendeleev’s periodic table
4) Thomson discovers the electron
5) Plum pudding model
6) Rutherford proposes the nucleus

Question 23

Isotopes

Answer 23

Atoms that have the same atomic number but different mass numbers

Question 24

Plum pudding model

Answer 24

Negative electrons spread throughout a positive material

Question 25

Net charge(total charge/ overall charge?)

Answer 25

= #Protons - #electrons

Question 26

Bohr model

Answer 26

Electrons orbit the nucleus like planets orbit the sun

Question 27

Quantam model

Answer 27

Electrons behave both as particles and waves

Question 28

Atoms gain or loose electrons to form

Answer 28

Ions

Question 29

Ion

Answer 29

atom or group of atoms with an overall charge

Question 30

average atomic mass

Answer 30

weighted average of the different isotopes of an element