C1-Atomic Structure and Periodic Table Flashcards
What is the radius of an atom?
0.1 nanometres (1 x 10^-10m)
Reason of 10 being to power of -10 instead of -9 is because it is 0.1nm not 1nm.
Describe the Nucleus of an atom
1) It’s in the middle of the atom
2)Contains Protons (+) and Neutrons (=)
3)Has a radius of around 1 x 10^-14m (around 1/10000 of the radius of an atom)
4) Positive charge bc of protons
5)Almost whole mass of atom is concentrated in nucleus
Describe the Electrons in an atom
1)Move around nucleus in electron shells
2)Negatively charged and tiny, but cover a lot of space
3)Volume of their orbits determines size of atom
4)Electrons have virtually no mass
State the relative mass and charge of:
-Proton
-Neutron
-Electron
-Proton has mass of 1 and charge of +1
-Neutron has mass of 1 and charge of 0
-Electron has mass of 0 (or very small) and charge of -1
How come atoms are neutral (have no overall charge)? (Unlike ions)
They have the same number of protons as electrons.
This means the charges cancel out.
What is an ion?
An ion is an atom or group of atoms that has lost or gained ELECTRONS, so is charged.
Number of protons≠Number of electrons.
What does it mean if an ion has a charge of 2-?
Remember when writing charge of ions the + or - comes AFTER number.
That ion has two more electrons than protons
What does it mean if an ion has a charge of 2-?
Remember when writing charge of ions the + or - comes AFTER number.
That ion has two more electrons than protons.
What is the nuclear symbol of an atom?
The letters that are used as its place holder in the periodic table and its mass and atomic number. E.g.
23
Na
11
What does the atomic number (bottom number) tell you?
How many protons there are
What does the mass number (top number) tell you?
Total number of protons and neutrons in atom.
How would you get number of neutrons from atomic number and mass number?
Subtract atomic number from mass number.
Remember when writing in standard form
To not write 1nm as 1 x 10^-9nm!
Write it as 1 x 10^-9m as the prefix nano means 1 x 10^-9!
Define an element
A substance made up of atoms that all have the SAME number of PROTONS in their nucleus.
What are the symbols for these elements?
-Carbon
-Oxygen
-Sodium
-Iron
-Carbon=C
-Oxygen=O
-Sodium=Na
-Iron=Fe
Define an isotope
Isotopes are different forms of the same element, which have the same number of protons(and electrons) but a different number of neutrons.
What does this mean about the atomic and mass number of an isotope?
They have the same atomic number but a different mass number
When talking about Isotopes, why is Ar used instead of the mass number when referring to the element as a whole?
Because many elements can exist as a number of different isotopes.
What is Ar?
An average mass taking into account the different masses and and abundances (amounts) of all the isotopes that make up the element.
How do you calculate Ar/relative atomic mass?
Ar= sum of (isotope abundance x isotope mass number)/ sum of abundances of all the isotopes
sum of (isotope abundance x isotope mass number) just means that you would do this for all of the isotopes present and then add the answers together.
Are there any units for Ar?
Nope, just the number
Define a compound
Compounds are substances formed from two or more elements which are chemically bonded (atoms are held together by chemical bonds)
What does making bonds involve?
Atoms giving away, taking or sharing electrons.
During a chemical reaction…
at least one new substance is made
What does a compound which is formed from a metal and non-metal consist of and what is this bonding called?
It consists of ions, the metal atoms LOSE electrons to form + ions and non-metal atoms GAIN electrons to form - ions.
Metals always LOSE electrons, Non-metals always GAIN electrons.
This is called IONIC Bonding.
How does ionic bonding work?
The opposite charges of the ions (positive and negative) mean they are strongly attracted to each other. The forces between these ions are strong electrostatic forces.
A compound formed from two non-metals…
is a Covalent compound
Describe the qualities of Fluorine
Very reactive, poisonous yellow gas
Describe the qualities of Chlorine
Fairly reactive, poisonous dense green gas
Describe the qualities of Bromine
Dense, poisonous, red-brown volatile liquid
Describe the qualities of Iodine
A dark grey crystalline solid or a purple vapour
Halogens all exist as molecules which are…
Pairs of atoms, they travel in twos
