Ions,Atoms, and Isotopes Flashcards
Atom
An atom is one of the basic units of matter.Everything around us is made up of atoms.
What are the subatomic particles?
Protons
Neutrons
Electrons
Where are protons and neutrons located?
Protons and neutrons exist in a dense core at the centre of the atom.This is called the nucleus and it is positively charged.
Charges of subatomic particles?
Protons(+1)
Neutrons(0)
Electrons(-1)
Where are electrons located?
The electrons are spread out around the edge of the atom.They orbit the nucleus in layers called shells.
Relative mass of subatomic particles?
Proton(1)
Neutron(1)
Electron(1/1840)
Mass number and atomic number
4
He
2
4 is the mass number
2 is the atomic number
What is the mass number?
the total number of protons and neutrons in a nucleus.
What is the atomic number?
the number of protons in the nucleus of an atom.
What value is equivalent to proton value?
The amount of electrons.
Describe three differences between the nuclear model of the atom and the plum pudding model.
1Alpha particles scattering experiment
2 The positive charge in the Nucleus
3 The electrons and nucleus are seperate
How does the alpha particle scattering experiment lead to a change in the model of the atom from the plum pudding model?
Most alpha particles went through the gold foil and hit the lithium detector.The mass of the atom is concentrated in the nucleus,centre of most of the atom is empty space.Some were deflected which meant the nucleus was positively charged.
What is an isotope?
Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei
What is an ion?
an ion is an electrically charged particle produced by either removing electrons from a neutral atom to give a positive ion or adding electrons to a neutral atom to give a negative ion.
Ionic bond
Electrostatic force of attraction between oppisitely charged ions.
Why do ionic compounds have a high melting and boiling point?
Ionic bonds are very strong. Therefore a lot of energy will be required to break the strong electrostatic force of attraction between oppositely charged ions.
When atoms form ionic bonds atoms from:
GROUP 1 form 1+ ions
GROUP 2 form 2+ ions
GROUP 3 form 3+ ions
GROUP 4 do not form ions(apart from tin and lead)
GROUP 5 form 3- ions
GROUP 6 form 2- ions
GROUP 7 form 1- ions
GROUP 0 never form ions in compounds.
What is a lattice?
A regular repeated three dimensional arrangement of atoms,ions ormolecules
When are ionic compounds usually formed?
When metals react with non-metals.
Properties of ionic compounds?
High melting and boiling points
solid
They are brittle
Usually soluble in water (aqueous).
Do not conduct electricity in solid forms,although the ions are charged they cannot move
They do conduct electricity when they are melted(molten) or dissolved as the ions are then free to move
