C2 - Elements, Compound and Mixtures Flashcards
What is chromatography?
The separating of a mixture to identify its (constituent) substances.
What is the Rf Value and how can it be calculated?
How far a substance has moved up from the starting line.
Rf value = distance substance moved / distance mobile phase moved.
What is the process that a solid turns to a gas called?
Sublimation
List the names of the processes of these changes in the states of matter.
a. Solid - Liquid
b. Liquid - Gas
c. Gas - Liquid
d. Liquid - Solid
a. Melting
b. Evaporation/boiling
c. Condensing
d. Solidification/freezing
How do changes in state happen?
Energy is needed to overcome the electrostatic forces of attraction between particles to melt/evaporate.
What is a physical change and what is a chemical change?
Physical change = no new substance made.
Chemical = new substance made
What are the state symbols and their meanings?
s (solid)
l (liquid)
aq (aqueous) [new substance in the solution]
What are the particles, relative mass (RFM) and relative charge?
Particle. Mass. Charge
Proton. 1. +1
Neutron. 1. 0
Electron. (0). -1
An electrons charge is very small, not quite 0 but near enough.
1/1860
What atoms that gain/loose electrons called?
Ions
How do you calculate the mass number of an atom?
Protons + Neutrons
What is an isotope?
Same number of protons, different number of neutrons.
How was the periodic table originally ordered?
Then, who changed it?
By atomic weight
Mendeleev said it made sense to swap the elements, leading to there being gaps for elements that were yet to be discovered.
What are the electron shell orders?
2,8,8,2
What is to the left and what is on the right go the periodic table?
On the left is all the metals and on the right is all the non metals.
Metals form positive ions
Non-metals form negative ions
What are group one metals?
Alkali metals, one electron in the outer shell, which means they are highly reactive and want to loose the electron.
