Chemistry Basics Flashcards
(40 cards)
Element
a pure substance that is comprised of only one type of atom
e.g. oxygen, gold nugget
Compound
a pure substance that is comprised of more than one type of atom
e.g. water: hydrogen atoms and oxygen atoms
Isotopes
Atoms of the same element, but with a different number of neutrons
How are atoms neutral?
atoms are neutral since protons are the same as electrons
electrons are negatively charged
cations are positive ions
-> to become a cation, they need to lose electrons
anion are negative ions
-> to become an anion, they need to gain electrons
Ions
Atoms with unequal charges, resulting in either an overall positive or negative charged
Cations
Anions
Cations: atoms that are positively charged
Anions: atoms that are negatively charged
Why do pure metals in group 1 and 2 elements need to be stored in oil?
Pure metals are highly reactive to water and oxygen, so oil helps to keep them from reacting explosively or dangerously.
group 13 usually doesn’t need oil as they have less reactivity
Subatomic particles: their electric charges
proton: positive
electron: negative
neutron: neutral/no charge
Electronic configuration
2,8,8,2
Electronic configurations of:
- boron
- argon
- calcium
- calcium ion
boron: 2,3
argon: 2,8,8
calcium: 2,8,8,2
calcium ion: 2,8,8
Types of atoms involved in different types of atomic bonding
Depending on the type of atom, different types of atomic bonding occurs
covalent bonding: non-metal atoms
ionic bonding: metal AND non-metal atoms
(metallic bonding)
Describe the bonding of the reaction:
sodium + chlorine -> sodium chloride
sodium (metal cations join together by metallic bonding) + chlorine (non-metal atoms join together by covalent bonding) -> sodium chloride (metal cations and non-metal anions join together by ionic bonding)
Covalent bonding
Non-metal atoms held together by sharing (valence) electrons, forming discrete molecules
Ionic bonding
3D lattice of metal cations and non-metal anions, held together by electrostatic attraction
(attracted by oppositely charged ions )
e.g. sodium + chloride reaction: both are cations and anions, opposite charged ions
When comparing ionic and covalent bonds, which type is the strongest?
covalent bonds
ionic bonds are held together by electrostatic attraction, but can be weakened by external factors like being dissolved in water
covalent bondings are bonded together as they share electrons, and are drawn towards the nucleus of the atom, so full outer shell of atom creates more stability
When comparing ionic and covalent bonds, which type of bonding can form 3D lattices?
both can form 3D lattice
When comparing ionic and covalent bonds, which type of bonding can form molecules?
covalent bonding
Ionic compounds
ionic compounds are usually salt e.g. sodium chloride as they were bonded from ionic bonding (opposite charges)
What do ionic compound formulas tell you?
ionic compound formulas tell you the ratio of ions in the lattice
Hydrogen peroxide (chemical formula: H2O2) ratio
2 hydrogen atoms and 2 oxygen atoms in the molecule
Magnesium chloride (chemical formula: MgCl2) ratio
ext: what type of bond?
ionically bonded
1:2 ratio of cations to anions
Polyatomic ions
Ions that contain more than 1 atom bonded together (they are in single unit due to their tight bond)
e.g. ammonium ion NH4+, sulphate ion SO4 2-
What types of chemical bonding are found in (NH4)2SO4
ionic and covalent bonding
Formula for:
- dihydrogen sulphide
- sodium bromide
- dinitrogen tetroxide
- aluminium sulphate
- iron carbonate
- diphosphorous pentoxide
- dihydrogen sulphide = H2S
- sodium bromie = NaBr
- dinitrogen tetroxide = N2O4
- aluminium sulphate = Al(SO4)3
- iron carbonate = Fe2(CO3)3
- diphosphorous pentoxide= P2O5
