Module 2-Foundations Of Chemistry Flashcards
What is the relative mass and charge of a proton?
Relative charge=+1
Relative mass= 1
What is the relative charge and mass of a neutron?
Relative charge=0
Relative mass=1
What is the relative charge and mass of an electron?
Relative charge= -1
Relative mass= 1/1836
What is the bond angle for a linear shape?
180
What is the bond angle for a trigonal planar?
120
What is the bond angle for a tetrahedral?
109.5
What is the bond angle for a octahedral?
90
What is the order of energy levels up to 4f?
1s,2s,2p,3s,3p,4s,3d,4p,4d,4f
How much does one lone pair compress the shape of a molecule?
2.5
How many s-orbitals are there?
one
How many p-orbitals are there?
Three
How many d-orbitals are there?
Five
How many f-orbitals are there?
Seven
How many electrons can a s-orbital hold?
Two
How many electrons can a p-orbital hold?
Six
How many electrons can a d-orbital hold?
Ten
How many electrons can a f-orbital hold?
Fourteen
Difference between sub-shell and orbital. (Amount of electrons it can hold)
Each orbital can only hold two electrons whereas the electrons a sub shell can hold depends on the energy level.
Describe what is meant by the term of ionic lattice in terms of type and arrangement of particles.
Repeating pattern of oppositely charged ions.
What is room temperature and pressure?
20 degrees and 101KPa
How do you convert from degrees C to Kelvin?
1 degree C:273K
What scale is used to measure electronegativity?
The pauling scale
In a non-polar bond is the bonded electron pair shared equally or unequally?
Unequally
The number of which sub atomic particle determines the strength of the London forces?
Electron
How do the London forces come about?
When there is an uneven distribution of electrons in an atom at any instant. This leads to instantaneous dipoles. Instantaneous dipoles induces a dipole in nearby molecules and induced dipoles attract each other.
Does permanent dipole-dipole interactions occur in a polar or non polar molecule?
Acts between different Polar molecules.
Describe the bonding in simple molecular structures.
Atoms within the same molecule are held by strong covalent bonds and different molecules are held together by weak intermolecular forces.
In which direction of the periodic table does electronegativity increase?
Top right, towards fluorine
What does it mean when the bond is non-polar?
The electrons in the bond are evenly distributed.
How is a polar bond formed?
Bonding atoms have different electronegativities.
What are the three intermolecular forces?
London forces (Induced dipole-dipole interactions)
Hydrogen bonds
permanent dipole-dipole interactions
Describe permanent dipole-dipole interactions.
When a molecule with a permanent dipole is close to other non-polar molecules, it causes the non-polar molecule to become slightly polar leading to attraction.
What are two anomalous properties of water?
1) Ice (solid) is less dense than water (liquid). Hydrogen bonds hold water molecules apart in an open lattice structure so water molecules in ice are further apart than in water.
2) Water has a relatively high melting and boiling point.
Hydrogen bonds are extra forces to break over London forces and hydrogen bonds are very strong.
Properties of An ionic compound.
-High melting and boiling point due to the large quantity of energy needed to overcome strong attraction between ions
-Conducts electricity only when melted as in a solid the ions are in a fixed position so there are no mobile charge carriers
Properties of a giant covalent lattice
- High melting and boiling point due to large number of covalent bonds
- Does not conduct electricity in any state as all electrons are involved in a covalent bond so no free electrons
Properties of a metallic compound
-high melting and boiling point due to the energy required to overcome attraction between positive ions and free electrons
-Conducts electricity in all states due to delocalised electrons
What are the nonpolar properties?
- Only contain one type of element so no difference In electronegativity
- Hydrocarbons
- Symmetric
What is the definition of orbital?
A region that can hold up to two electrons
What letter represents the atomic number of an atom?
Z
What does the atomic number tell about an element?
number of protons
How is mass number calculated?
Number of protons + number of neutrons
How to calculate the number of neutrons?
Mass number - atomic number
Define isotope.
Atoms of the same element with different numbers of neutrons
Why do isotopes of the same element react in the same way?
- Neutrons have no impact on the chemical reactivity
- Reactions involve electrons, isotopes have the same number of electrons in the same arrangement
What are ions?
Charged particles formed when an atoms gains or loses an electron
Define relative atomic mass.
Weighted mean mass of an atom of an element compared to 1/12th of the mass of a carbon-12 atom
Define relative isotopic mass
The mass of an atom of an isotope compared with 1/12th of the mass of an atom of carbon-12
Do metals usually gain or lose electrons?
Lose
What is an empirical formula?
Simplest whole number ratio of atoms of each element present in a compound
