QUESTIONS AND ANSWERS
sustainable chemistry - ANSWER -designed to meet the needs of the present
generation without compromising the needs of future generations
Matter - ANSWER -Anything that has mass and takes up space
mass - ANSWER -A measure of the amount of matter in an object
weight - ANSWER -A measure of the gravitational force exerted on the matter of
an object.
Classes of Matter - ANSWER -Solids, Liquids, Gas
Solid - ANSWER -Definite shape and volume
vibration
ice, brick, wood,
liquid - ANSWER -A state of matter that has no definite shape but has a definite
volume.
move in irregular pattern
petrol, vinegar, paint, water
gas - ANSWER -A state of matter with no definite shape or volume
freely move continuously- far apart
helium, oxygen, carbon monoxide, hydrogen
melting point - ANSWER -The temperature at which a solid becomes a liquid
Vaporation - ANSWER -Liquid to gas
boiling Point - ANSWER -temp at which liquid escapes and becomes a gas
,condensation - ANSWER -Gas to liquid
freezing - ANSWER -liquid to solid
occurs at freezing point/same as melting point
Sublimation - ANSWER -A change directly from the solid to the gaseous state
without becoming liquid
Ex: dry ice
2 categories of matter - ANSWER -substances and mixtures
Substance - ANSWER -A single kind of matter that is pure and has a specific set
of properties.
Substance contains - ANSWER -Elements and Compounds
Elements - ANSWER -A molecule composed of one kind of atom; cannot be
broken into simpler units by chemical reactions.
represented by chemical groups:
Cl, H, Mg
Compounds - ANSWER -2 or more elements chemically combined
many exist as groups of atoms bonded together as molecules
Atoms - ANSWER -Building blocks of matter
smallest particle in an element
Aristotle - ANSWER -A Greek Philosopher,
all matter is composed of 4 elements
all matter is continuous not atomistic
WEAF- water, earth, air, water
Atomos - ANSWER -Lecuippus/democritus
point at which matter can no longer be subdivided
, Mixtures - ANSWER -A combination of two or more substances that are not
chemically combined
homogeneous mixture - ANSWER -a mixture that is uniform in composition;
components are evenly distributed and not easily distinguished
Ex: sugar and water
heterogeneous mixture - ANSWER -A mixture that is not uniform in
composition; components are not evenly distributed throughout the mixture
Ex: oil and water
Measurement of Matter - ANSWER -mass
Measurements of length - ANSWER -meters
1 m= 100 cm
1000 m=1 km
0.0254 m = 1 inch
Measurement of mass - ANSWER -kilograms
0.454 kg=1 lbs
1 kg= 2.2 lbs
.001 kg= 1 g
1g= 1000 mg
Measurement of volume - ANSWER -liter (L)
1 gal = 3.79 L
.26 gal= 1 L
1000 ml = 1 L
measurement of time - ANSWER -seconds
measurement of temperature - ANSWER -Kelvin (K)
Amount of substance - ANSWER -mole (mol)
, A mole of a substance - ANSWER -is the amount of a substance which contains 6
X 10^23 particles of that substance
Measurement of electric current - ANSWER -ampere
when moving to a bigger unit- divide
when moving to smaller unit- multiply
Convert 0.0123456 km to m - ANSWER -move decimal 3 places to right
12.3456 m
Convert 25 kg to g to mg - ANSWER -25 kg = 25,0000 g= 25,000000 mg
Density - ANSWER -mass/volume
Calculate Density of Metal Sample with a mass of 18.96 g and a volume of 4.32
cm3 - ANSWER -D= M/V
D= 18.96g/4.31 cm3
D= 4.40 g/cm3
Energy - ANSWER -the ability to do work
the ability to change matter, physically or chemically
Types of energy - ANSWER -potential and kinetic
potenial energy - ANSWER -energy that is stored in an object due to its position
or condition of an object.
kinetic energy - ANSWER -Energy in motion (gases)
Heat - ANSWER -The energy transferred from a hotter object to a cooler one
Measurement of heat - ANSWER -calories or joules
1 cal is the amount of heat required to change the temp of 1.00 g of water at 1.00
degrees C
1 cal= 4.184 J