2.1, 2.5

Question 1

Distinguish between the two broad types of matter

Answer 1

substance - matter with a fixed composition
mixture - two or more substances that are physically combined with a variable composition

Question 2

what can substances be further subdivided into?

Answer 2

elements and compounds

Question 3

define an element

Answer 3

the simplest type of matter with unique physical and chemical properties

Question 4

4 properties of an element

Answer 4

• consists of only one kind of atom
• each element is unique because the properties of its atoms are unique
• in nature, most elements exist as populations of atoms
• several elements occur in molecular form

Question 5

define a compound

Answer 5

consists of two or more different elements bonded chemically with a fixed number of atoms of each element

Question 6

how do mixtures differ from compounds?

Answer 6

• components of a mixture can vary in their parts by mass
• a mixture retains many of the properties of its components
• mixtures can be separated into their components by physical changes; chemical changes are not needed

Question 7

compare heterogeneous mixtures and homogeneous mixtures

Answer 7

heterogeneous:
- one or more visible boundaries among the components
- the composition is not uniform throughout the mixture, but rather varies from one region of the mixture to another

homogeneous:
- has no visible boundaries
- has a uniform composition
- components are uniformly intermingled on a molecular level

Question 8

draw a flow diagram for the different types of matter

Answer 8

p.46

Question 9

where does staircase on the periodic table lie?

Answer 9

boron/aluminium -> silicon

Question 10

metals

Answer 10

shiny solids at room temp (except mercury), conduct heat and electricity, malleable, ductile

Question 11

nonmetals

Answer 11

gases or dull brittle solids (except bromine), conduct heat and electricity poorly

Question 12

metalloids

Answer 12

B, Si, Ge, As, Sb, Te
have properties between those of metals and nonmetals

Question 13

lanthanides

Answer 13

top row

Question 14

actinides

Answer 14

bottom row

Question 15

elements in a group have —— chemical properties; elements in a period have ——- chemical properties

Answer 15

similar; different