Atoms, Bonding and Ions Flashcards
Particles
All matter in the universe is comprised of atoms
Matter
Anything that takes up space is matter
Groups
Each group in the periodic table correlates to how many electrons each atom has in its outer shell
What is the mass number?
The top number, representing the number of protons and electrons
What is the atomic number?
The bottom number, representing the number of protons
Shells
Electrons orbit in shells of 2-8-8-8-….
Cation
A positively charged ion
Anion
A negatively charged ion
How do you represent the electrons added to anions?
Use a dot
What bonding is a metal and a non-metal?
Ionic bonding
Electrostatic
The forces between two oppositely charged ions that hold them together
When can a covalent structure conduct electricity?
When it is molten or dissolved
What is the outer shell called?
The valence
What type of bonding occurs when a non-metal reacts with another non-metal
Covalent bonding
What type of boiling point to covalent structures have?
Low boiling points because they have weak intermolecular forces
Can covalent structures conduct electricity
No because they have no charge carriers
What is covalent bond?
A shared pair of electrons, they are strong.
The bigger the molecule the stronger the what?
The stronger the intermolecular forces
Diatomic
Two atoms in a molecule
What is special about the ratio of a nanoparticle
Nanoparticles have very large surface area to volume ratios so their properties are changed
What does the prefix nano mean?
one billionth
What are they used in?
Medicine, sun-cream and cosmetics/ deodorants
Why are the used in medicine?
They can be used to deliver drugs to specific areas rapidly, eliminates unwanted side effects and helps prevent infections however long term effects are unknown and it is expensive
Why are they used in sun-cream
Makes sun-cream more effective for protecting skin, invisible on skin however there is a possibility the nanoparticles are small enough to accumulate in the body as nps clump together
Why are they used in cosmetics and deodorants
Can be added to toothpastes to be more effective, silver nps kill odours but there is concern they may again accumulate in the body
What did John Dalton discover?
A scientist that drew on ancient Greek philosophy and came up with a sphere
What did JJ Thompson discover?
He discovered electrons and came up with the plum pudding model
What did Niels Bohr discover?
His calculations led to an understanding of electron orbitals or shells. He also found that the nucleus was not just a lump of positive mass but particles of positive charge
What did Ernest Rutherford discover?
Along with Geiger and Marsden, he conducted the gold foil experiment and found hat some alpha particles bounced back when pointed at a gold leaf sheet meaning there was a small mass in the middle that was positive
What did James Chadwick discover?
There was a particle in the centre that had mass but no charge (the neutron)
