Pre-Test
This is the smallest part of an element.
atom!
Objects with the same charge do this when they come close to each other.
Repel
Three subatomic particles.
protons, neutrons and electrons
The sum of protons and neutrons in the nucleus of an atom.
mass number/ nucleon number
Objects with different charges do this when they come close to each other.
Attract
Located outside of the nucleus and have a negative charge.
electrons
The number of protons in an atom of a certain element.
atomic number/ proton number
what type of the ion formed when an atom gains electrons?
negative ion/ anion
Electrons are located outside of the nucleus. True or False?
True! Electrons are on the energy levels.
When an atom gains an electron it has this kind of electrical charge.
negative
Located inside of the nucleus and have a positive charge.
protons
The atomic number of Oxygen.
8
What is the charge on the ion formed from Group II metal?
+2
When an atom loses an electron it has this kind of electrical charge.
positive
The mass number of Potassium.
39
What is the charge on the ion formed from Group VI metal?
-2
This is the smallest subatomic particle.
An atom that is neither positively or negatively charged.
neutral
An atom with the same number of protons but different number of neutrons.
isotope
Mass number - atomic number = ______ __ ________.
number of neutrons
What is the formula of hydroxide?
OH-