Chemistry Flashcards
(57 cards)
What are atoms?
The smallest units of matter that make up elements can’t be created or destroyed. They are made up of protons, neutron and electrons.
What did Dalton believe?
Using his solid sphere model in 1803, Dalton believed atoms were invisible, ones of the same element were identical, ones of different elements were different and atoms had no subatomic particles.
What did Thompson believe?
Using his plum pudding model composed in 1904, Thompson discovered electrons existed within atoms and that they had an overall positive charge
What was Rutherford’s experiment?
He fired positively charged alpha particles at a thin sheet of gold foil.
What did Rutherford believe?
Using his nuclear model in 1911, Rutherford believed atoms were mostly made up of empty space and that the nucleus had a positive charge. He didn’t explain why electrons remain in orbit around the nucleus and didn’t include neutrons
What did Bohr believe?
Using his planetary model composed in 1913, Bohr believed electrons orbit the positively charged nucleus in fixed energies and sizes, that electrons emit energy and collapse into the nucleus
How are elements represented in the periodic table?
Chemical symbols
How is the periodic table arranged?
In groups (columns) that indicate the number of valence electrons and periods (rows) that indicate the number of electron shells
What are the physical properties of metals/non-metals?
- Solubility
- Boiling point
- Ductility
- Malleability
- Lustre
- Conductive
What are the chemical properties of metals/non-metals?
- Flammability
- Radioactivity
- Oxidation
- Corrosive
- Toxicity
- Explosive
How to write the symbol of an atom/isotope
Put the atomic weight at the top and the atomic number on the bottom and then having the chemical symbol of the atom next to it.
What does the atomic number indicate?
The number of protons and electrons in the atom
What does the mass number indicate?
The sum of the protons and neutrons within the atoms
How can the number of neutrons be found?
Subtracting the atomic number from the mass number
Describe Bohr’s model
Also known as the planetary model
Consists of a positively charged nucleus with electrons orbiting in in. fixed electron shells that indicate orbit strength.
What is the number of electrons an atom needs to gain, lose or share dependant on?
How many electrons needed to have a full outer shell of valence electrons so the atom has a stable electron configuration
Why are noble gasses stable and unreactive?
They contain full outer shells which is the aim of chemical bonding.
What is an ionic bond?
The transfer of electrons between metallic and non metallic ions that are oppositely charged creates a strong electrostatic force e.g. NaCl
What is a covalent bond?
When two non metal ions share electrons in order for them both to have a full outer shell e.g. H2
What is a metallic bond?
When metal cations form a lattice causing the electrons to detach from their atom and for a delocalised sea where they are free to float throughout the structure e.g. Au
How does an ion gain a charge?
Based on the different number of protons and electrons when it has a full outer shell
What is the difference between a cation and an anion?
A cation is formed by metals and is positively charged and an anion is formed by non-metals and is negatively charged
What are diatomic molecules?
A form of some elements that consist of two atoms. A mnemonic to remember them is:
Have
No
Fear
Of
Ice
Cold
Beer
What are some examples of ionic compounds?
Sodium chloride (NaCl)
Aluminium oxide (Al2O3)
Sodium sulfide (Na2S)
Magnesium chloride (MgCl)
Calcium chloride (CaCl2)
