Particle Theory
Which state of matter has particles closest together?
Solid
Burning wood is what type of change?
Chemical change
What does atomic number represent?
Number of protons
What would we use to measure the height of something?
Ruler
What process do we follow to conduct our experiment?
The Scientific Method
What happens to particles when a substance is heated?
They move faster
Kimchi is made through fermentation.
Is fermentation a physical or chemical change?
Chemical change
Where are protons found in an atom?
Nucleus
What do both graphs and tables need to be labeled with?
A title
What do we look for in the results of an experiment?
Patterns
Why can gases be compressed?
The particles are far apart
Gas, temperature change, colour change, new substance
How do you find the number of neutrons?
Mass number – atomic number
What goes on the x-axis of a line graph?
The independent variable
What do we write before beginning an experiment to express what we believe will happen?
A hypothesis
Describe particle movement in a liquid.
Close together, but can move past each other
A candle is lit. What two types of change are happening?
Physical (melting wax) + Chemical (burning)
A neutral atom has an atomic number of 12, and a mass of 24.
How many protons, neutrons, and electrons does it have?
12 protons
12 electrons (neutral)
12 neutrons (24 – 12)
What is the name for a data point that does not fall close to the line of best fit?
An outlier
In a scientific experiment, why do we need to keep some variables controlled?
To make sure our results only came from what we changed
Explain what happens to particles during a chemical reaction.
Atom rearrange to form new substances
Ethanol is first frozen and then burned.
What types of changes are occurring? Explain your answer.
Freezing ethanol → Physical
It is only changing state (liquid to solid), no new substance is formed.
Burning ethanol → Chemical
It reacts with oxygen to form new substances (CO2 and H2O) and releases energy (heat).
An atom has 17 protons and 18 electrons.
Is this atom neutral or an ion? Explain your answer.
Ion, negative charge (-1), because it has more electrons than protons.
What kind of error does a broken measurement scale produce?
Systematic error
How can we reduce the effect of errors in our experiments?
Conducting an experiment with multiple trials and calculating the average (mean)