unit 2: physical properties, prefixes, s.i. units

Question 1

strength

Answer 1

ability to support a heavy load without changing shape permanently/ breaking

Question 2

hardness

Answer 2

ability to resist being scratched?
ability to scratch another material

Question 3

flexibility

Answer 3

ability to bend without breaking and return to its original shape

Question 4

melting/boiling point

Answer 4

temperature at which material changes from solid to liquid/liquid to gas

Question 5

electrical conductivity

Answer 5

measure of how early an electric current passes through it

metals have good electrical conductivity while non-metals have poor electrical conductivity

Question 6

thermal conductivity

Answer 6

measure of how easily heat passes through

metals have good thermal conductivity while non-metals have poor thermal conductivity

Question 7

density

Answer 7

amount of matter an object had in proportion to its volume

Question 8

prefix: mega (state the symbol and index notation?)

Answer 8

M (1 000 000 or 10^6)

Question 9

prefix: kilo (state the symbol and index notation?)

Answer 9

k (1000 or 10^3)

Question 10

prefix: deci (state the symbol and index notation?)

Answer 10

d (1/10 or 10^-1 or 0.1)

Question 11

prefix:centi (state the symbol and index notation?)

Answer 11

c (1/100 or 10^-2 or 0.01)

Question 12

prefix: milli (state the symbol and index notation?)

Answer 12

m (1/1 000 or 10^-3 or 0.0001)

Question 13

prefix: micro (state the symbol and index notation?)

Answer 13

idk how to type the sign: upside down h? or u with a line

1/ 1 000 000 or 10^-6 or 0.0000001

Question 14

properties of metals?

Answer 14

malleable, ductile, sonorous, shiny appearance, good electrical and thermal conductivity

Question 15

properties of non-metals?

Answer 15

brittle, not sonorous, dull appearance, poor electrical and thermal conductivity

Question 16

s.i unit for length?

Answer 16

metre, symbol: m

Question 17

s.i. unit for mass?

Answer 17

kilogram, symbol: Kg

Question 18

s.i. unit for time?

Answer 18

second, symbol: s

Question 19

s.i. unit for electric current?

Answer 19

ampere, symbol: A

Question 20

s.i. unit for temperature?

Answer 20

kelvin, symbol: K

Question 21

how to calculate density?

Answer 21

mass per unit volume

density = mass/volume

Question 22

when are s.f. and d.p. used?

Answer 22

d.p. for ‘+’ and ‘-‘
d.p. for average
s.f. for ‘x’ and ‘÷’

Question 23

what can digital calipers measure? + what is the scale of them?

Answer 23

outside jaws measure external diameter
inside jaws measure internal diameter
tail measures depth
the scale is in ‘mm’