C1 Atomic structure and periodic table Flashcards
define element
made up of the same type of atom and cannot be chemically split up further
define compound
two or more different atoms that are chemically bonded
define mixture
two or more atoms that are not chemically bonded
define empirical formula
The simplest ratio of atoms of each element in a compound
define empirical formula
The simplest ratio of atoms of each element in a compound
how do you calculate the empirical formula?
- count up number of each type of ion
- divide by the smaller number
- round to the nearest whole number
define solute
the name of what you dissolve
define solvent
the name of what you dissolve the solute in
define solution
the outcome of dissolving the solute in the solvent
define soluble
a name you give to a substance that can be dissolved
define insoluble
a name you give to a substance that cannot be dissolved
define solubility
the amount of solute that can be dissolved in 100g of solvent
through which experiment did John Thompson discover electrons mainly?
The Vaccum Tube
what did the experiment The Vacuum Tube show?
showed negatively charged particles flowing through an electrical current
what misconception did John Thompson think about electrons after the Vacuum Tube experiment?
he thought that electrons were part of the atom because they were much smaller and alike
what model of the atom did John Thompson make after the Vacuum Tube experiment?
the plum pudding model
describe the plum pudding model
had an area of positive space and had negative electrons randomly spotted in the middle
what experiment did Ernest Rutherford do?
the alpha particle scattering experiment
what was the alpha scattering experiment?
fired alpha particles (He2+ ions) at a piece of gold foil
what 4 things did Ernest Rutherford learn about the atom from the alpha particle scattering experiment?
- there is a positive nucleus in the middle
- electrons are around the nucleus
- the mass of the atom is concentrated at the middle
- most of the atom is space
how did Ernest know that there is a positive nucleus in the middle from the a.p.s experiment?
the particles were reflected/refracted by this and re-directed
how did Ernest know that the mass of the atom is concentrated in the middle from the a.p.s experiment?
some of the particles were deflected and some of them went straight through
describe what changes Bohr made to the nuclear model
he put electrons set distance from the nucleus and they are orbiting it, these are called shells/energy levels
describe 4 differences between the nuclear model and plum pudding model?
-plum pudding model has no nucleus
-in the ppm the mass was evenly distributed but in the nm its concentrated in the middle
-most of the nm is space but in the ppm there are no spaces
-in the ppm electrons are randomly plotted around but in the nm they are around the positive nucleus
why are lithium and sodium both in group 1?
they both have 1 electron in their outer shell
explain why sodium is more reactive than lithium
-sodium has more shells/its a bigger atom
-weaker force of attraction between outer electron and positive nucleus
-makes the outer electron easier to lose
give 2 observations you can see when potassium is added to water
-fizzing with bubbles
-the potassium floats on the water