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.
How do we find the charge of an anion?
If an ion gains one electron, the charge is -1. If an ion gains two electrons, the charge is -2.
Example of an anions symbols?
A chlorine atom gains one electron and so it has a charge of -1. This is represented as Cl-.
What are ionic compounds?
An ionic compound is a compound made up of cations and anions.
What are ionic compounds made up of?
Ionic compounds are made up when anions and cations come together, they form compounds made up of large crystal lattices.
Example of ionic compound
Common tables salt is an ionic compound. It is made up of sodium and chloride, and its chemical name is sodium chloride.
What do metals form?
Metals always form cations?
What do non-metals form?
Non-metals always form anions
Are cations always metals or non-metals?
Cations are always metals
Are anions always metals or non-metals?
Anions are always non-metals
What is electron configuration?
The number of electrons in each of the electron shells of an atom.
What does the group that an element is in tell us?
The group tells us how many electrons are in the outer shell
What are Nobel gases?
Nobel gases are stable, they cannot combine. Nobel means a full outer shell
What does group 1 react strongly with?
Group 1 reacts strongly with water
What does the period an element is in mean?
The period an element is in is the amount of electron shells it has
How many elements are in the periodic table?
The are 120 elements.
How many metal elements are there?
92 metal elements
How many non-metal elements are there?
28 non-metal elements
