An element that is shiny
and that conducts heat and
electricity well
What is a metal?
A group of atoms held together by chemical bonds.
What is a molecule?
What is the atomic number of a sodium atom that has 11 protons and 12 neutrons?
What is 11?
True or False: An atom can form bonds by gaining, losing, or sharing electrons with other atoms.
What is true?
The smallest particle of an element that has the chemical properties of that element.
What are atoms?
An element that conducts
heat and electricity poorly
What is a nonmetal?
This forms when an atom gains or loses one or more electrons. An ______ is a particle with a positive charge or negative charge
What is an ion?
Elements in the same ________ on the periodic table have the same number of valence electrons.
What is a group?
This guy found out that atoms have nuclei which contain protons.
Who is Ernest Rutherford?
What are the parts of an atom? Describe their charges (or lack thereof).
Proton - Positive
Electron - Negative
Neutron - No charge
An element that has
properties of both metals
and nonmetals
What is a metalloid?
The current atomic theory suggests that electrons move within an area around the nucleus called the
What is the electron cloud?
Properties of elements within a _________ on the periodic table change in a predictable way from one side of the table to the other.
What is a period?
Greek philosopher who thought that you would eventually end up with a particle that could not be cut. He called this particle atomos.
Who is Democritus?
The atomic number is equal to
The number of protons
A ________ joins atoms together in a water molecule.
What is a chemical bond?
The total number of protons and neutrons in an atom’s nucleus is equal to the
What is mass number?
True or False: The four valence electrons of a carbon atom are in its outermost energy level.
What is true?
This person's theory stated that all matter is made up of atoms. He also thought that atoms cannot be created, divided, or destroyed. His theory also stated that all atoms of a certain element are identical. But they are different from atoms of all other elements.
Who is John Dalton?
_________ is the weighted average of the masses of all the naturally occurring isotopes of that element
What is average atomic mass?
2 Parts:
A bond formed by atoms sharing electrons.
________ forms between metal atoms when their outermost energy levels overlap.
What is a covalent bond? AND: What is a metallic bond?
Dmitri Mendeleev’s arrangement of the elements became known as the
What is the periodic table?
Which of the following can happen during a chemical change?
A. Atoms change into new types of atoms.
B. Bonds break, and new bonds form.
C. Nuclei of atoms break apart and combine.
D. All of the electrons in the atom are lost.
What is B. Bonds break, and new bonds form.
In his model, electrons move around the nucleus in circular paths. Each path is a certain distance from the nucleus.
Who is Niels Bohr?
Name two of the three different models used to represent atoms.
The Bohr model, electron cloud model, and space-filling models *Make sure you know these for the test