Matter
What are the 3 states of matter?
Solid, Liquid, and Gas
What is a chemical property?
A property describing how a substance can change into a new substance
What is a physical property?
A property observed without changing the substance
What is the difference between a physical change and a chemical change?
Physical = no new substance; chemical = new substance formed
What is a pure substance?
Matter made of only one type of particle
What is density and how is it calculated?
Measures how tightly packed matter is within an object. Mass divided by volume
Give one example of a chemical property
Flammability, reactivity, corrosion, toxicity, acidity/basicity
Name two examples of physical properties.
Colour, density, solubility, conductivity, hardness, melting point
Give one example of a physical change and one example of a chemical change.
Examples: melting ice (physical), burning a match (chemical)
What is a mixture?
Two or more substances physically combined
What is the name of the process when solid turns directly to gas?
Sublimation
What does flammability describe?
How easily an object is set on fire
How can you use density to figure out if an object will float or sink in water?
Lower density = float
Higher density = sink
What happens to matter during a chemical change?
New substances are formed through rearrangement of atoms
Explain how filtration or evaporation can separate mixtures.
They use physical methods to separate substances
The density of an object is 2 g/mL and it's volume is 4 mL. What is the mass of the object?
8 grams
Why is reactivity considered a chemical property?
It describes how easily a substance reacts to form new substances
What is the difference between mass and weight?
Mass = amount of matter; weight = force of gravity
Why is dissolving salt in water a physical change but burning paper is a chemical change?
Salt dissolves with no new substance; burning forms new substances
Classify saltwater as a pure substance or a mixture and explain your reasoning
Mixture — it is a solution made of salt and water physically combined
Name all the parts of the Kinetic Molecular Theory (Hint: There are 4!)
1. All matter is made of very small particles
2. There is empty space between particles
3. Particles are constantly moving
4. Energy makes the particles move
Explain how rusting shows a chemical property of iron.
Iron reacts with oxygen to form rust (new substance)
Explain how solubility is a physical property and give an example.
Solubility describes how well a substance dissolves (e.g., salt in water)
A student heats a blue solid and it turns into a yellow gas that does not change back when cooled. Is this a physical or chemical change? Explain with at least 2 reasons.
Chemical.
1. Color Change
2. Cannot change back.
What is the difference between a homogeneous and heterogeneous mixture?
Homogeneous = evenly mixed (coffee and milk); heterogeneous = unevenly mixed (milk and cereal)