Science Ch.1 Introduction to Chemistry Review Sheet

What is a chemical change?

A change that produces one or more new substances (changes the identity of the substance)

Define exothermic change

A change where energy is released, indicates by a heating of the area around it

Define endothermic change

A change where energy is taken in, indicated by a cooling of the area around it.

Define Physical Property

A characteristic of a substance that can be observed without changing it into another substance. Each element can be identified by its specific physical and chemical properties.

Define molecule

A group of 2 or more atoms held together by a chemical bond

Define solution

A homogeneous mixture (You cant see the different parts)

What is density?

A measure of how mass is in a given volume

Define temperature

A measure of the average energy of motion of the particles of matter

Define substance

A single kind of matter that is pure, having a specific makeup or composition and set of properties

Define compound

A substance made of 2 or more chemically combined into a set ratio

What are the different characteristics of a compound?

A substance made of 2 or more elements chemically combined in a set ratio. When elements are combined they have properties that are different from those of the uncombined elements.

Define element

A substance that cannot be broken down into any other substances by chemical or physical means. The elements have different properties because their atoms are different

What is matter?

Anything that has mass and takes up space

What is similar between an element and a compound?

Both are substances

What is the formula for water?

H2O

Why is weight not a constant measurement?

It can change based on altitude and location

How can you use the density of an object to determine if it will float or not?

It it is denser than a fluid it sinks, if it is less dense it floats

What are the SI units or measuring mass?

Kg and grams

Define mixture

Made of 2 or more substances (elements, compounds., or both) Each substance keeps its original properties

What are examples of chemical properties?

Rust, combustion (ability to burn), tarnishing

Define chemical formula

Shows the elements in the compound and the ratio of the atoms

Define mass

The amount of matter in an object

Define volume

The amount of space that matter takes up

Define atom

The basic particle from which all elements are made,

Define chemical energy

The energy stored in the chemical bonds between atoms

Define weight

The measure of the force of gravity on an object

Define chemistry

The study of matter and how matter changes

Define thermal energy

The total energy of all the particles in an object

Define homogeneous mixture

When the substances are so evenly mixed that you cannot see the different parts

Define Heterogeneous mixture

When you can see the different parts

Define Chemical Property

a characteristic of a substance that describes its ability to change into different substances

What is an example of a mixture that is a solution?

air or pool water

What happens during a physical change?

alters the form or appearance of matter but does not make any substance in the matter into a different substance, doesn't change the identity of the substance

What does every chemical or physical change in matter include?

change in energy

What is the term for the force that holds two atoms together?

chemical bond

What are the 2 units for measuring volume?

cm^3 or mL

What is the ability to do work called?

energy

Where does thermal energy naturally flow?

from warmer matter to cooler matter

How do you find volume?

length x width x height

What does the law of conservation of mass state?

mass is not created or destroyed in a chemical or physical change

What are 4 measurable properties of matter?

mass, weight, volume, and density

How do you calculate density?

mass/volume

If you pour several liquids into the same container, once they settle, where will you find the most and least dense?

most dense at the bottom, least dense at the top

What is an example of a mixture that is not a solution?

soil or salad

What are examples of physical properties?

states of matter (solid, liquid, gas) color, shape, form, and dissolving

Describe what happens when a candle burns

the wax dosn't disseapear, instead it is first melted and then changed into smoke