The Atom Flashcards
Where are protons located in an atom?
Protons are located in the nucleus of an atom
Where are neutrons located in an atom?
Neutrons are located in the nucleus of an atom
What is the number of protons equal to?
The number of protons an atom has is equal to its atomic number
Protons are equal to electrons - true or false
True
Where are electrons located in an atom?
Electrons spin around the nucleus in electron shells (clouds)
PEA rule
Protons = Electrons = Atomic number P = E = A
How is the number of neutrons in an atom calculated?
Mass number - Atomic number = Neutrons
How many electrons can fit on the 1st electron shell?
2 electrons
How many electrons can fit on the 2nd electron shell?
8 electrons
How many electrons can fit on the 3rd electron shell?
18 electrons (except for the first 20 elements, in which case the 3rd shell can only hold 8)
What is an ion?
An ion is an atom that has lost or gained electrons and therefore has an electric charge.
What is an atom?
The fundamental building block of all materials
What does an atom consist of?
It consists of a cluster of protons and neutrons surrounded by a cloud of electrons
What is the difference between an atom and ions?
While atoms are electrically neutral and have an equal number of protons and electrons, ions do not have an equal number of protons and electrons which causes the atom to have an either positive or negative charge.
What is a cation?
A cation is a positively charged ion
How are cations formed?
Cations are formed when an atom loses electrons.
Why will an ion tend to form a cation?
An ion will tend to form into a cation if it’s outermost electron shell is mostly empty. The atom will usually lose all the electrons in the outer shell so that only filled shells remain.
How is a cation symbol represented?
The symbols used to represent cations are made up of the atomic symbol and the charge of the ion.
How do we find out the charge of a cation?
If an element loses one electron from its outer shell, the ions charge will now be +1.
If an element loses two electrons, the ion will be +2.
Example of a cations symbol.
Sodium atoms lose one electron, so the sodium ion has a charge of +1. This is represented by the symbol Na+
What is an anion?
An anion is a negatively charged ion.
How are anions formed?
An anion is formed when an atom gains electrons
When will an ion tend to form an anion?
An ion will tend to form an anion is the outermost shell of the atom is almost full. In that case the atom gains additional electrons until the shell is full.
How is an anion represented?
The symbol used to represent anions is made up of the atomic number for the atom and the charge of the ion.
