Lab safety/equipment
List three pieces of equipment that may be commonly used in a lab.
Thermometer
Bunsen Burner
Beaker
Measuring cylinder
List 5 elements
e.g. Gold, silver, iron, Aluminium, magnesium
What are the three states of matter?
Solids, liquids and gases
Is boiling water a physical or chemical change?
Physical change
What are two things you have learned in science this term so far?
e.g. difference between physical and chemical changes / different between elements, compounds and mixtures.
List three general lab rules.
Tie up hair, wear safety glasses and no food or drinks inside the lab.
Give 3 examples of a mixture
Salty water
Sugar in water
Milo in milk
A cup of coffee
Is melting chocolate a reversible change?
Yes
Which one is a physical change and which one is a chemical change?
Chocolate melting
Baking a cake
physical - chocolate
chemical - cake
What is it called when liquid turns to gas?
Evaporation
Scenario:
Jackson began weighing chemicals, and some splashed onto his hands. He was curious what the chemical tasted like, so he licked his finger.
What two rules did Jackson break?
-If chemicals splash on skin or clothing, rinse immediately with large quantities of water.
-The teacher must be immediately notified in the event of an accident.
Give 3 examples of a compound
Vinegar
Baking soda
What are the two main processes that are the reason for changes of states of matter. i.e. Solid to liquid / liquid to gas
Heating and cooling
What is the easiest way to tell if a change was physical or chemical?
Reversible or irreversible change
What is it called when gas turns to liquid? What is one example of this in nature?
Condensation
We see this as clouds are formed
When using a measuring cylinder, the shape of the liquid will be curved. What is the name of this curve?
The meniscus
What is the difference between a heterogenous mixture and a homogenous mixture?
A heterogeneous mixture has a non-uniform composition, meaning its composition varies from one location to another.
A homogeneous mixture has a uniform composition, meaning its appearance and composition are the same, no matter where you take a sample.
Explain how the particles behave in a solid, a liquid and a gas.
Solid: tightly packed, dense
Liquid: more fluid, less densely packed
Gas: More actively, more spread out
Give 3 examples of a chemical change and 3 examples of a physical change.
Chemical: Cooking, burning, rotting
Physical: Mixing, cutting paper, making a cup of tea
Can you pour solids, liquids or gases? If so, how is this possible?
Liquids and gases can be poured. This is possible because particles can move around and are not fixed. This is because the forces between particles in a liquid are weaker than a solid and weakest in gases.
Come up with a scenario where students should have been following these rules:
-Always wear your goggles
-Do not enter stock/supply rooms
e.g. A student walked into the supply room and accidentally spilled chemicals into their eyes.
Provide a detailed answer for: What is the difference between elements, compounds and mixtures.
An element is a pure substance (1 type of atom).
Compounds are substances that contain two or more different types of atoms.
A mixture is a combination of substances that can be physically separated. The particles in a mixture are not joined together by chemical bonds.
Give a real life example of how particles could be arranged in a solid, a liquid and a gas
Solid: students sitting at assembly
Liquid: Students walking around in a classroom
Gas: A game of football
List three indications for a chemical change
Permanent colour change
Gas given off (bubbles)
Temperature change
Precipitate forms
Racing car tires are not inflated to the correct pressure before a race. Why is this? Hint: Think about what happens during a race.
As the car goes around the track, the tires get warm from friction. This causes energy to be transferred to the gas particles inside the tire. Therefore the gas particles collide more frequently and with more force against the walls of the tires. If the tire was fully inflated, it wouldn't have room for this to happen and it may burst.