CHEMISTRY DEFINED

Chemistry

the study of matter and the way it changes

we try to understand these changes by doing experiments

Chemistry

we make a hypothesis based

on what we think will happen

we make observations based on what happens in the experiments

2 types of observations: qualitative & quantitative

Chemistry

we try to extend our knowledge based on our observationscalled an inference

we can draw conclusions based on our observations

Matter

anything that has mass and takes up space (occupies volume)

consists of virtually everything around us

ex: iPod, air, desk, hair, plant, etc.

Hypothesis

an educated guess as to what will happen in an experiment

by doing experiments, a

hypothesis is either

supported (accurate)

or unsupported (inaccurate)

Qualitative

observation based on words & description

gathered using your 5 senses state, colour, shape, texture, odour,

lustre, … ex: The substance is a shiny, grey,

opaque solid

Quantitative

observation based on numbers

mass, melting point, density, volume, … ex: The substance has a density of 2.7

g/cm3

Observation

something you see, hear, touch, taste, or smell

Candle Activity

Inference

assumption or judgement based on observations that you’ve made

ex: you can infer that the flame was hotter than your body temperature, even though you didn’t test it

Observation or Inference? She’s carrying a lot of books. She must be

a smart girl. His car is a rally red 1971 Cuda. The motor

is well-maintained. He has big muscles. He works out a lot. He overcooked the meat. He’s a bad cook. He ran the 100m dash in 11.85 seconds.

He finished 3rd in his heat. She drives a nice car. I bet she’s rich.