An atom is
What is the smallest unit of an element?
An element is
What is a substance that cannot be separated or broken down into simpler substances?
The order of elements arranged in the modern periodic table is based on this number
What is atomic number?
When energy or heat is added into a chemical reaction
What is endothermic reaction?
Elements are arranged in in these ways on periodic table, going down a column and across a row
What is a group and period?
Three subatomic particles of an atom
What is Proton, Neutron, Electron?
The element for "O"
What is Oxygen?
These are found on the periodic table
What is an element?
A school bus burning gas as it drives students to school giving off exhaust fumes is an example of what
What is exothermic reaction?
As you move down a group on the periodic table, this increases
What is electron shells?
These 2 subatomic particles make up the nucleus of an atom
What is proton and neutron?
The element for symbol "C"
What is Carbon?
What is protons?
In chemical reactions atoms cannot be what
What is created and destroyed?
The outermost electrons in an atom are called this
What are valence electrons?
This subatomic particle has a negative charge
What is an electron?
The element for symbol "Be"
What is Beryllium?
Atomic mass represents the total number what
What are protons and neutrons?
The starting materials in a chemical reaction or equation
What is reactant?
The starting materials in a reaction or equation
What is a proton and electron?
The element for symbol "He"
What is Helium?
The atomic mass of Lithium is
What is 7?
In a reaction, everything to the right of the equation is called this
What is product?
Nonmetals are found on this side of the periodic table
What is the right side?