Introduction to Chemistry
What is Chemistry?
Chemistry is the study of what things are made of, how they behave, and how they can change to form new substances.
Which apparatus is used to measure small amounts of liquid?
Dropper
Differentiate between solid, liquid and gas based on their volume.
Solid and Liquid: fixed volume
Gas: no fixed volume
What kind of change happens when a new substance is formed?
Chemical Change
What is a pure substance?
A pure substance is made up of one type of particle. It has a fixed composition and constant properties.
Define Matter.
Matter is anything that has mass and takes up space.
What is the main apparatus used in heating a liquid?
Bunsen burner
Which process occurs when a solid is changed to a liquid?
Melting
Differentiate between solid, liquid and gas based on their shape.
Solid: Has its own shape
Liquid: Takes the shape of its container
Gas: Has no shape
What is a molecule?
Molecules are groups of atoms bonded together. eg. water
Give an example of a matter and non-matter item in this room.
matter: book, desk, chair, pen, tv, whiteboard etc,
non-matter: feelings, knowledge, light, sound etc
Name one safety procedure that you should always follow in the lab
No eating/drinking, No Playing, Always listen and follow instructions, Tie back long hair, Wear protective gears, etc
Matter can be divided into two different properties. What are they?
Chemical and Physical properties
Which process occurs when a liquid changes to a solid?
Freezing
Give a definition for a mixture?
A mixture is made up of two or more substances physically combined. It has variable composition and properties.
Which branch of Chemistry studies what substances are made up of and is mainly used in analyzing blood samples and testing water?
Analytical Chemistry
True or False? If there is an emergency, we should always pick up our belongings and run to the nearest exit.
State why.
In an emergency we should form a line and move in an orderly manner to the emergency exit.
Describe what change of state occurs in sublimation?
Solid to gas or gas to solid with our changing to the liquid state.
Describe what change of state occurs in evaporation?
liquid to gas
Which 2 elements / atoms can be found in the water molecule?
Hydrogen and Oxygen
Which branch of Chemistry studies carbon containing compounds and is used in medicines, plastics and foods?
Organic Chemistry
Which apparatus is used to hold and heat small amount of liquid?
Test tube
Differentiate between solid, liquid and gas based on their forces of attraction.
The forces of attraction between solid particles are strong, liquid are weak and gases are very weak.
Differentiate between solid, liquid and gas based on their arrangement of particles.
Solid particles are close together and in a fixed position. Liquid particles are in a random arrangement and move freely but are close together. Gas particles are free and far apart in a random arrangement.
Why does salt water boil at a higher temperature than water?
The salt ions mix with the water molecules and hold them more tightly together, therefore, the water molecules then need more energy (higher temperature) to break free.