Chemical Reaction and Conservation of Mass Test

Atom

the basic unit of a chemical element.r

proton

a subatomic particle with a positive charge. it appears in the nuclei (innermost ring) of an atomic structure.

neutron

a subatomic particle with a neutral charge. it appears in the nuclei (innermost ring) of an atomic structure.

electrons

a subatomic particle with a negative charge. it appears in the second and third rings of an atomic structure.

products

new substances that result from a reaction. they are on the right side of the equation

reactants

two substances that come together to produce a reaction. they are on the left side of the equation

Chemical Changes

A chemical change is any change that causes a new substance to be formed. For example, when the camp fire has burned completely out, what's left behind? Ashes! Ash is a new substance formed due to the burning of another substance, wood. This is a chemical change.

physical changes

The changes in which only physical properties of substances are changed and no new substance is formed is called a physical change. It is a reversible change. Example: Boiling and freezing of water.

chemical properties

Chemical properties are characteristics that can only be measured or observed as matter transforms into a particular type of matter. Reactivity, flammability, and the ability to rust are among them.

physical properties

A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Physical properties include color, density, hardness, and melting and boiling points

molecules

group of atoms bonded together,

conservation of mass

mass can neither be created or destroyed

chemical reaction

In a chemical reaction, bonds between atoms in the reactants are broken and the atoms rearrange and form new bonds to make the products. for example, combustion is a chemical reaction.

8 main forms of energy

light energy, heat energy, mechanical energy, gravitational energy, electrical energy, sound energy, chemical energy, nuclear energy