What is chemistry?
This is the study of matter, what it is made of, and how it changes.
What is carbon dioxide?
Plants take in this gas from the air and use it to make their own food during photosynthesis.
What is the name of this equipment?![]()
beaker
What is an element?
A pure substance made of only one type of atom.
What is a mixture?
A combination of two or more substances that are not chemically bonded.
What is a liquid?
This state of matter can flow to take the shape of its container, but it always keeps the same volume.
What is ice?
Solid water floats in liquid water because it is one of the very few substances that becomes less dense when it freezes.
Name of this equipment?
test tube
What does the atomic number tell us?
The number of protons in an atom's nucleus. Or the order of the element in periodic table
Is air a mixture or a pure substance?
Mixture. Air contains several gases, including nitrogen, oxygen, and carbon dioxide.
What is evaporation?
You see this physical change when a rain puddle slowly disappears on a sunny day.
Which gas makes up the largest percentage of Earth's atmosphere?
Nitrogen (N₂).
This tall, narrow container is marked with detailed lines to measure exactly how much liquid is inside.
graduated cylinder
Which element has the symbol O?
oxygen
How can you separate sand and water?
By filtration.
What is the nucleus?
This tiny, dense center of an atom holds all of its protons and neutrons.
A balloon is filled with helium. Why does it rise in air?
Helium is less dense than the surrounding air, so the buoyant force can lift the balloon.
Tripod
An atom has 11 protons. What element is it?
Sodium (Na).
How can you separate salt from salt water?
By evaporation. The water evaporates and the salt remains.
What is rusting (or oxidation)?
This chemical change occurs when iron reacts with oxygen and water, creating a flaky, red-brown substance on an old bike chain.
A student is given a substance that contains hydrogen and oxygen. The substance always contains hydrogen and oxygen in a fixed ratio, and it has properties completely different from the elements hydrogen and oxygen.
Question: Is the substance an element, mixture, or compound? Explain your answer.
Compound.
Hydrogen and oxygen are chemically bonded in a fixed ratio, producing a new substance with different properties.
name of this equipment?
Bunsen burner
What is the difference between an element and a compound?
Element: contains only one type of atom.
Compound: contains two or more different elements chemically bonded together.
A mixture contains iron filings, sand, and salt. Describe how you would separate all three substances.