Chapter 1- The Atom

Question 1

Who is J.J. Thomson?

Answer 1

He use the cathode ray tube to find that the ray is formed by negatively charged particles (electrons)

Question 2

What does the Plum Pudding Model show, and who was it created by?

Answer 2

• It was created by JJ Thompson

- shows the mass of the Adam is evenly distributed and positively charged taking up space not occupied by the electrons

Question 3

Who is Ernest Rutherford?

Answer 3

• Created a model of an atom that had a nucleus
• he use the gold foil experiment it shows that the nucleus had a positive charge and the atom is mainly made up of empty space

Question 4

What is the Planetary Model?

Answer 4

• also called the Bohr’s model

- Showed a center, nucleus, and rings of orbiting electrons

Question 5

What are Valence electrons?

Answer 5

The outermost electrons located in the Valence shell

Question 6

What is the Wave-Mechanical-Model?

Answer 6

Shows that atom with a nucleus and orbitals

Question 7

What are the mass of protons?

Answer 7

1.67 x 10 ^-24 g

Question 8

What is the definition of atomic number?

Answer 8

The number of protons in the nucleus of an atom

Question 9

What are isotopes?

Answer 9

Atoms of the same element that have different numbers of neutrons or different mass numbers

Question 10

What is Dalton’s Theory of the atom?

Answer 10

• All elements are composed of indivisible atoms
• All atoms of a given element are identical
• Atoms of different elements are different that is they have different masses
• Compounds are formed by the combination of atoms of different elements

Question 11

What is the definition of atomic masses?

Answer 11

The average mass of all isotopes in a sample of an element

Question 12

What is the ground state?

Answer 12

When electrons occupy the lowest available orbitals

Question 13

What is the excited state of an electron?

Answer 13

When electrons absorb energy and temporarily moved to a higher energy level

Question 14

How long does an excited electron stay at the higher energy level?

Answer 14

Only stays at the higher energy level temporarily

Question 15

What is a Homogeneous matter?

Answer 15

A material that has a uniform composition throughout

Example: sugar water

Question 16

What is heterogeneous matter?

Answer 16

Materials made up of parts with different chemical and physical properties
Varying composition
not uniformly mixed or dispersed

Question 17

What is the definition of Pure Substance and the two types?

Answer 17

A pure substance is a matter that has the same composition throughout the sample
The two types are elements and compounds

Question 18

What are Elements?

Answer 18

Elements are substances that cannot be broken down or decomposed into simpler substances by chemical means

Question 19

What are Compounds?

Answer 19

Compounds are composed of two or more elements that are chemically combined it in a definite proportions by mass

Question 20

What is the Law of Definite Proportions?

Answer 20

The statement that types of atoms in a compound exist in a fixed ratio

Question 21

What is the definition of mixtures?

Answer 21

Mixtures are combinations of two or more pure substances that can be separated by physical needs and not have fixed compositions

Question 22

What is an example of a mixture?

Answer 22

Iron and sulfur when mixed loses their own properties