Chapter 2-3, 2-4

Question 0

What are the unique properties of an element?

Answer 0

• Color
• Texture
• Melting point
• Color when burned

Question 1

Element

Answer 1

• The simplest form of matter that ha a unique set of properties
• Serve as the building block for all other forms of matter
• Composed of atoms that have the same number of protons, neutrons, and electrons as all other forms of the element
• Ex: Oxygen v.s Helium

Question 2

Atom

Answer 2

-A substance that cannot be broken down into simpler substances by chemical means

Question 3

Proton

Answer 3

-Particles with a positive charge

Question 4

Neutrons

Answer 4

-Particles with a neutral charge

Question 5

Electrons

Answer 5

-Particles with a negative charge

Question 6

Structure of an atom

Answer 6

• Subatomic particles: protons, neutrons, electrons

- Nucleus: is the center of the atom and consists of neutrons and protons

Question 7

Atoms and the periodic table

Answer 7

• The number of protons an atom has will dictate what element it is
• An atom can have any number of electrons and neutrons but only one number of protons

Question 8

What ways can atoms be represented?

Answer 8

• Diagram
• Colored circle (Ball and stick modeling)
• Element symbol (C)

Question 9

Compound

Answer 9

• A substance that contains two or more elements chemically combined in a fixed proportion
• Physical methods are used to separate mixtures that cannot break a compounds into simpler substances
• Ex: Carbon, oxygen, hydrogen are combined to the compound sucrose

Question 10

Chemical symbol

Answer 10

• Each element is represented by a one or two letter chemical symbol
• First letter= caps, second= lowercase

Question 11

Periodic Table

Answer 11

-Arranges the elements based on a set of repeating properties

Question 12

Period

Answer 12

-Each horizontal row of the periodic table

Question 13

Group

Answer 13

• Each vertical column of the periodic table

- Also called a family

Question 14

Properties of Compounds

Answer 14

• Different from their compounds elements
• Ex: Sugar= sweet, Carbon= tasteless black solid
• When two compounds are combined, their is a change in composition and a change in properties
• Ex: Sodium chloride (salt) is a white solid

Question 15

Breaking down compounds

Answer 15

• Electrical current passed through water, broken down into oxygen and hydrogen
• Carbon cannot be broken down into simpler substances

Question 16

Subatomic Particles

Answer 16

• Particles that are smaller than atoms.

- Protons, Electrons, Neutrons

Question 17

Nucleus

Answer 17

• Center of the atom

- Consists of neutrons and protons

Question 18

Lewis Structures (Lewis Dot Structure)

Answer 18

• Used complex molecules are being represented
• • Representations of molecules in which an atoms elemental symbol and solid lines are used to represent the components of a molecule.

Question 19

Chemical Change

Answer 19

• A change that produces matter with different composition than the original matter

Question 20

Who created chemical symbols?

Answer 20

• Swedish Chemist Jons Jacob Berzelius (1779-1848)

Question 21

Chemical Property

Answer 21

• The ability of a substance to undergo a specific chemical change
• Can be observed only when a substance undergoes a chemical change

Question 22

Chemical Reaction

Answer 22

-The process of how one substance becomes one or more new substances

Question 23

Four signs of chemical change

Answer 23

• Transfer of Energy
• Change in Color
• Production of a gas
• Formation of a precipitate

Question 24

Precipitate

Answer 24

• A solid that forms and settles out in a liquid mixture

- Occurs during some chemical changes

Question 25

Law of Conservation of Mass

Answer 25

• During any physical change or chemical reaction, mass is conserved
• Mass is neither created or destroyed