week 1, concept 2 : Classifying matter (matter and atoms)

Question 1

Answer 1

concept 2 :

classifying matter

Question 2

Answer 2

chapter 2

atoms

Question 3

classification of matter

(visual)

Answer 3

Question 4

definition -

matter

Answer 4

anything that occupies space and has mass

Question 5

matter is physically separable into _

Answer 5

pure substance

and

mixtures

Question 6

Definition -

pure substance

Answer 6

• fixed composition
• cannot be further purified

Question 7

pure substances are_

Answer 7

• elements
• compounds (elements united in fixed ratios)

Question 8

elements cannot be_

Answer 8

• subdivided by chemical or physical means

Question 9

definition-

compound

Answer 9

• A pure substance
• that is made up of two or more elements in a fixed ratio by mass.

Question 10

definition-

mixture

Answer 10

• a combination of 2 or more pure substances

Question 11

Homogeneous matter =

Answer 11

• uniform composition throughout (mixture)
  (ie. sugar in water, salt water)

Question 12

Heterogeneous matter =

Answer 12

• non uniform composition
  (ie. sand and wate, or blood)

Question 13

Formula of a compound tells us _

Answer 13

• the ratios of its constituent elements
• and identifies each element by its atomic symbol.

Question 14

definition-

element

Answer 14

• A substance (for example, carbon, hydrogen, and iron) that consists of identical atoms.

Question 15

how many known elements?

Answer 15

116

Question 16

how many known elements occur in nature?

Answer 16

88

Question 17

other than the 88 elements that occur in nature, how do the others occur?

Answer 17

• have been made by chemists and physicists.

Question 18

what do the element symbols consist of?

Answer 18

one or two letters

Question 19

in a mixture the substance may be present is any mass ratio?

T/F

Answer 19

T

Question 20

in a mixture, each substance has a _

Answer 20

different set of physical properties.

Question 21

the 2 types of mixtures are?

Answer 21

• homogeneous
• heterogeneous.

Question 22

what type of representation of a water molecule is this?

Answer 22

Molecular formula

Question 23

what type of representation of a water molecule is this?

Answer 23

Structural formula

Question 24

what type of representation of a water molecule is this?

Answer 24

Ball and Stick model

Question 25

what type of **representation** of a water molecule is this?

Answer 25

Space-filling **model**

Question 26

how do chemists represent these compounds (3)

Answer 26

**Formulae** * **molecular formula** * **structual formula** * **ball and stick model**

Question 27

Co-efficient number:

Answer 27

how many molecules | (ie- H 2 0 , the co-efficient is 2)