It's Just a Phase...of Matter!
Why does the test tube feel warmer when zinc reacts with hydrochloric acid?
The test tube feels warmer because the reaction between zinc and hydrochloric acid releases heat — it’s a chemical reaction.
What does electrolysis mean?
To break apart by electricity
electr - as in electricity, and -lysis (which means to break apart)
What is the difference between a chemical and physical reaction?
A chemical reaction makes new substances, but a physical reaction only changes the form or state of a substance — no new substance is made.
What is the difference between mass and volume?
Mass is the amount of matter in an object (measured in grams or kilograms).
Volume is the amount of space an object takes up (measured in liters or cubic centimeters).
Why do we use many different ways to describe substances?
So we can understand what they are, how they behave, and how they are different from other substances.
What data will you need to determine whether a chemical reaction has occurred?
The change in properties.
Is electrolysis a physical or chemical reaction?
Chemical Reaction - it breaks compounds into new substances using electricity
What does it mean of a substance dissolves in water?
It is soluble.
What is the formula for density?
Mass/Volume = Density
What are the THREE atoms that make up water (H20)?
2 Hydrogen, 1 Oxygen
What is the conservation of matter?
A principle stating that matter cannot be created or destroyed in a chemical reaction; it is conserved.
What’s the main difference between boiling water and electrolysis?
The main difference is that boiling water is a physical change, while electrolysis is a chemical change.
Boiling only changes water from liquid to gas (no new substance).
Electrolysis breaks water into hydrogen and oxygen gases (new substances form).
What is the difference between the reactants and products (different substances) at the molecular level?
At the molecular level, reactants are the starting molecules that change during a chemical reaction, and products are the new molecules that are formed after the reaction.
What would you expect to float in water, a pencil or a coin? WHY?
A pencil would float and a coin would sink because the pencil is less dense than water, while the coin is more dense than water.
Why might hardness be an important property when choosing materials for building things?
Hardness is important because harder materials are better for things that need to resist scratching or breaking.
What are the properties of a strawberry?
Red, soft, sweet, has seeds, etc.
What happens to water particles when it boils?
When water boils, its particles gain energy and move faster.
If the atoms in a substance are rearranged into a new way, does it create a new substance?
If the same atoms are rearranged into a new combination, then a new substance is formed because the atoms are now joined in a different way.
If two objects have the same volume but different masses, what can you say about their densities?
If two objects have the same volume but different masses, the one with more mass is denser.
Why is bronze better than copper for tools?
Bronze is better than copper for tools because it is harder and stronger.
Is melting point a physical or chemical property?
Melting is a physical change, not a chemical reaction, because the substance only changes from solid to liquid and no new substance is formed.
Why do scientists use a control group when conducting an experiment?
Scientists use a control group to see what normally happens so they can compare it to the experiment.
What happens to the kinetic energy of particles in a metal washer when placed in hot water?
This means the particles move faster because heat energy from the water is transferred to the washer.
What is the unit of density in the metric system?
Cubic Centimeters (cm3)
What happens to iron when it rusts?
When iron rusts, it reacts with oxygen and water to form rust, which makes the iron weaker, flaky, and crumbly.