Atoms
Changes
Matter & changes
Chemistry
Chemistry & Atoms
100

Which group of elements contains a stable level of outer electrons for each element?

noble gases

100

a characteristic of something that can be observed without changing the essence of the object is called what? 

physical property

100

matter with no definite volume or shape is known as what?

a gas

100

What do we call the things on the left hand, or starting, side of a chemical reaction.

reactants

100

What type of compound has water attached to it?

a hydrate

200

the smallest piece of an element that still retains the properties of an element is known as what?

an atom, atom

200

A change from one substance to another is what type of change?

chemical

200

the most common state of matter in the universe is what?

plasma

200

What can we use to represent a chemical reaction using symbols and formulas?

a chemical equation

200

Dot diagrams are used to represent what?

valence electrons, outer electrons

300

What type of ion has more than one atom?

complex ion

300

a change in size, shape, or state of matter is what type of change?

physical

300
matter with a definite volume but not shape

liquid

300

a chemical reaction that combines two or more substances into another is known as what type?

synthesis reaction

300

how many atoms are in binary compounds?

two

400

what do we call the force that holds atoms together in a compound? 

a bond, bond

400

burning a log would be what type of change? 

chemical change

400

What do we call the temperature where a solid begins to liquify?

melting point

400

What do we call the substance that speeds up chemical reactions without changing ITS individual properties or composition?

catalyst, a catalyst

400

What number describes the number of protons in the nucleus of an atom?

atomic number

500

How many atoms are generally needed in the outer energy level of an atom for it to be stable?

8

500

The amount of energy needed to change a material from a liquid to a gas is the _____ ___ _________. 

heat of vaporization

500

the process that involves a solid turning directly into a gas without any intermediate stage is known as what?

sublimation

500

What do we call the energy needed to start a chemical reaction?

activation energy

500

Atoms of the same element that have differing numbers of neutrons can be called what? 

Isotopes