atomic structure 1 Flashcards
what is a chemical substance( an element) made of?
chemical substances are made of tiny particles called atoms which are the building blocks of all matter.
an atom is made up of three parts:
protons( + charge)
electrons( - charge)
neutrons ( neutral charge hence the name)
what are compounds , mixtures , elements?
Compound- 2 or more different elements that are chemically bonded together.
Element- can be found on the periodic table .
Mixture- 2 or more different elements together , may or may not be chemically bonded to each other ( they are all mixed ).
how to find the protons , electrons an neutrons in an atom
Proton- its atomic number you see at the top ( the smallest number on the element found on the periodic table)
Electrons- its the atomic number you see as well ( due the fact that the number of protons = number of electrons)
neutrons- its not displayed on the element ( the box where the numbers are stated , however you could do a math calculation:
mass number = # of protons + # of neutrons
to find neutrons:
of neutrons = mass number - # of protons
eg:
8 - the atomic number ( the number of protons and electrons)
O - the symbol
oxygen - name of the element / symbol
16- the mass number ( the number of protons + neutrons)
-> neutrons= 16-8 = 8
#electrons and protons= 8
the charges and masses of the protons , electrons and neutrons
MASS CHARGE
Electrons: 0 -1
Protons: 1 +1
Neutrons: 1 0
what are the rules to draw an electron configuration
1) find out what are the number of electrons there are for that atom - meaning go to the atomic number of that atom and write it down( for your sake)
2) you have to know that 1st shell holds 2 electrons
3) 2nd and 3rd shells hold 8 electrons( don’t need to know any further than that for gcse)
example: oxygen:
8 - atomic number
O
oxygen
16- mass number
1) we take 8 - since it is the number of protons(=to the number of electrons)
2) put 2 on the first shell (8-2=6)
3) 6 on the second shell( we have 0 left to put on the 3rd shell)
4) the electron configuration is (2.6)
how to know how many electrons or what group it is in
so in order to know what group it is in , you could count the outer shells meaning the 2nd shell
number of electrons on the outer shell (not 1st shell) = group
what is the word / symbol equation for water?
word equation:
hydrogen + oxygen -> water
symbol equation:
2H2 (g) + O2 (g) → 2H2O (l)
must learn formulas!
Carbon dioxide - CO2 Water- H2O Oxygen gas- O2 Hydrogen gas - H2 Nitrogen gas- N2 Ammonia - NH3 Hydrochloric acid- HCl Sulphuric acid - H2SO4
what is the word / symbol equation for carbon dioxide?
word equation:
carbon + oxygen -> carbon dioxide
symbol equation:
C + O2 → CO2
what is the word / symbol equation of ammonia?
word equation:
nitrogen + hydrogen-> ammonia
symbol equation:
N2 (g) + 3H2 (g) -> 2NH3 (g)
