Chapter 1 - Atomic Structure And The Periodic Table Flashcards
(28 cards)
Where is the nucleus in an atom located?
The Middle of an atom.
What does the nucleus of an atom contain?
Protons and Neutrons.
What is the charge of a nucleus and why?
Overall positive because the protons have a positive charge and neutrons have no charge.
Where is the majority of the atoms mass found?
In the nucleus.
What charge do electrons have?
A negative charge.
Where can electrons be found?
They occupy shells which orbit around the nucleus.
The charge of electrons equals the…
Same size and the protons, but opposite.
Properties of protons:
Heavy and positvely charged.
Properties of neutrons are:
Heavy and neutral [no charge]
Properties of electrons are:
Tiny and negatively charged.
How heavy are electrons?
They have virtually no mass.
What are the rules of electron shells?
- Electrons are in shells (or energy levels)
- The lowest energy levels are always filled first (closest to the nucleus.
- 2 electrons allowed in 1st shell. 8 electrons in 2nd shell. 8 electrons in 3rd shell.
- Atoms are better with full shells.
- When an outer shell isn’t full, atoms want to react.
How do you find out the electronic configuration of an atom?
- Find out number of protons (it equals the same electrons)
How many different types of atoms are in elements?
Elements only have one atom type.
What is the atomic number?
The bottom number on the element it tells us the number of protons in an atom (and electrons too)
What is the mass number of an element and what does it tell us?
Top number on element, it tells us the total number of protons and neutrons in the atom.
Why is the atomic number unique to an element?
No two elements have the same number of protons. (E.g oxygen only has 8 protons)
How can we tell the difference between mass number and atomic number?
The mass number is roughly double the atomic number - meaning the mass number is the bigger and the atomic number is the smaller one.
What are isotopes? Give an example.
They are different atomic forms of the same element e.g. Liquid oxygen and oxygen gas.
How are Isotopes different to their original forms?
They have exactly the same number of protons, but different mass numbers.
What is relative atomic mass?
the ratio of the average mass of one atom of an element to one twelfth of the mass of an atom
Steps to work out RAM?
- Multiply mass of each isotopes by the relative abundance.
- Add together.
- Divide by sum of relative abundances.
What is relative abundance?
How much there is of each isotope compared to the total amount of the element in the world.
When was the discovery of the periodic table?
1869.