From Atoms To Molecules Flashcards
Atomic number is the number of…
Protons
Mass number is the number of…
Protons and neutrons
Isotopes are…
The same number of protons but different number of neutrons.
Cations have more…
Protons than electrons
Anions have more…
Electrons than protons
Elements are…
Atoms of one type
Compounds are…
Atoms of two or more different elements join
Molecules are…
Atoms that are stuck together
Mole is…
Avogadro’s number
6.022x10*23
Molarity is…
The number of moles of solute per litre of solution
Relative mass is…
The weighted average of all isotopes
Molecular weight is…
The mass of a molecule of a substance.
Molar mass is…
The mass of one mole of substance
What happens when we go across the periodic table?
Atomic size decreases
Number of valence electrons increases
Electronegativity increases
Oxidising nature increases
What happens when we go down the group on the periodic table?
Atomic size increases
Number of valence electrons remains the same
Electronegativity decreases
Oxidising nature decreases
What is the definition of organic chemistry?
The chemistry of carbon compounds.
What are atomic orbitals?
Electrons are grouped into different shells at different distances from the nucleus.
What is the principle quantum number
n
Is the number of shells
How many electrons can each shell contain?
2n*2
What are the energy levels of the shells?
Further from the nucleus has a higher energy level.
As it can hold more electrons.
How many and what sub shells are there?
4 subshells (s,p,d,f)
What shape is the s orbital?
Spherical
What shape is the p orbital?
Two slim spheres on top of each other.
What shape is the d orbital?
4 long tear drop shapes attached at their tails, equally separated.
What shape is the f orbital?
8 tear drop shapes attached at their tails separated equally (360)
How many orbitals does the s subshell contain?
1
How many orbitals does the p subshell contain?
3
How many orbitals does the d subshell contain?
5
How many orbitals does the f subshell contain?
7
The definition of electronic configuration of atoms is…
The number of electrons that an atom possesses, and the orbitals in which those electrons are placed in.
What are the valance electrons?
Electrons on the outer most shells.
The definition of valence is…
The number of electrons an atom must lose or gain to attain the nearest noble gas.
What is the Aufbau Principle of ground-state electronic configuration?
Orbitals and shells fill in order of increasing energy.
What is the Pauli Exclusion Principle of ground-state electronic configuration?
Each atomic orbital can hold a maximum of 2 electrons.
What is the Hunds rule for ground-state electronic configuration?
When there are 2 or more orbitals of the same energy, electrons go in different directions.
What is the octet rule?
Atoms transfer or share electrons to attain a filled shell of electrons (noble gases).
What is ionic bonding?
Transferring electrons from one atom to another.
Ions have opposite charges, and they attract each other to form an ionic bond.
Covalent bonding is…
Electrons are shared rather than transferred.
Non-polar covalent bonds is when…
Electrons are shared equally.
Polar covalent bonds are…
Unequally shared pair of bonding electrons.
What is the definition of electronegativity?
Power of an atom in a molecule to attract electrons to itself.
What is the definition of bond polarity?
The amount of partial charge multiplied by the bond length.
The 3 different types of intermolecular forces are…
1) dipole-dipole interactions
2) van der walls forces
3) hydrogen bonding
What is a dipole-dipole interaction?
Interactions between the positive end of one dipole and the negative end of another dipole.
What are van der walls forces?
Relatively weak forces of attraction that exist between non polar molecules.
What is hydrogen bonding?
Attractive force between the H attached to an electronegative atom of one molecule and an electronegative atom of the same or different molecule.
sp3 hybridisation is…
C forms 4 single bonds
sp2 hybridisation is…
C forms a double bond
sp hybridisation is…
C forms a triple bond or accumulate double bond.
