BTEC Applied Science Unit 1 questions
and answers
What is Hund's rule? (Think bus seats!) - ANSWER-Orbitals must all be singly filled
before they can be doubly occupied
Which elements do not fill the 4s subshell before the 3d subshell? - ANSWER-Copper
and chromium
Define the term ionic bond - ANSWER-The electrostatic attraction between oppositely
charged ions
What is the charge of an ion from group 1? - ANSWER-+1
What is the charge of an ion from group 2? - ANSWER-+2
What is the charge of an ion from group 6? - ANSWER--2
What is the charge of an ion from group 7? - ANSWER--1
Explain how atoms of sodium react with atoms of chlorine - ANSWER-Na loses its 2s1
electron gaining a +ve charge.
Cl gains an electron in the 3p subshell gaining a -ve charge.
The opposite charges attract to form NaCl
Why do ionic bonds have such high melting points? - ANSWER-Each +ve ion is
surrounded by 6 -ve ions and vice versa.
Strong electrostatic attraction in every direction.
Requires a large amount of energy to break
,State two factors that affect the strength of an ionic bond - ANSWER-Size of ion and
charge on ion
When can ionic substances conduct electricity? - ANSWER-When molten or in aqueous
solution
Describe the properties of ionic compounds - ANSWER-Conduct electricity when molten
or aqueous solution
High melting/boiling points
Usually soluble in water
Define the term covalent bond - ANSWER-A shared pair of electrons
Which metals lose electrons from the 4s subshell before the 3d subshell? - ANSWER-
Transition metals
Why do metals have such high melting points? - ANSWER-Strong force of attraction
between positive ions and delocalised electrons. This requires a large amount of energy
to overcome.
State the two factors that affect the strength of metallic bonding - ANSWER-Size of ion
Charge on ion
Explain why metals conduct electricity - ANSWER-The delocalised electrons 'carry'
charge. Current flows because of this.
Explain why metals conduct heat - ANSWER-Particles are paced tightly so kinetic
energy is passed from ion to ion. The delocalised electrons also enable heat to be
passed.
Explain why metals are ductile and malleable - ANSWER-The lattice structure allows
layers of metal ions to slide over each other without disrupting bonding
Explain how the charge on metal ions affects the strength of the metallic bond -
ANSWER-The larger the +ve charge the greater the attraction between the nucleus and
the delocalised electrons
Explain how the size of the metal ions affects the strength of the metallic bond -
ANSWER-The smaller the +ve ion the closer the nucleus is to the delocalised electrons
creating a greater attraction
Name the 3 forces between molecules - ANSWER-Van der Waals
Permanent dipole-dipole
Hydrogen bonds
, Order the 3 forces between molecules in order of strongest to weakest - ANSWER-
Hydrogen bonds
Permanent dipole-dipole
Van der Waals
How are Van der Waal's forces formed? - ANSWER-Electrons move to one side,
caused temporary dipole. This induces a temporary dipole in neighbouring molecules.
Attraction occurs between oppositely charged dipoles
In what molecules do Van der Waal's forces exist? - ANSWER-Non-polar molecules
How are permanent dipole-dipole forces formed? - ANSWER-Permanent dipole in one
molecule attracts oppositely charged permanent dipole in neighbouring molecule
In which molecules do permanent dipole-dipole forces exist? - ANSWER-Polar
molecules
Which elements must be present for hydrogen bonds to exist? - ANSWER-Hydrogen
and either nitrogen, oxygen or fluorine
What is meant by the term displacement? - ANSWER-When a more reactive element
takes the place of a less reactive element in a compound
State the equation for determining moles - ANSWER-Moles = mass ÷ relative atomic
mass (molar mass)
Define the term Avogadro's Constant - ANSWER-The number of atoms in a mole of a
given substance. Quoted as 6.02x10^23
Define the term relative atomic mass - ANSWER-The average mass of an atom of an
element relative to 1/12th the relative atomic mass of Carbon12
Define the term relative molecular mass - ANSWER-The average mass of a molecule
relative to 1/12th the relative atomic mass of Carbon12
What does this number represent? 6.02x10^23 - ANSWER-The number of particles in a
mole. Commonly called Avogadro's Constant
What is the equation for calculating % yield? - ANSWER-% yield = (actual yield ÷
theoretical yield) x 100
What groups are included in the 's' block of the periodic table? - ANSWER-Groups 1
and 2
What part of the periodic table is known as the 'd' block? - ANSWER-Transition metals
and answers
What is Hund's rule? (Think bus seats!) - ANSWER-Orbitals must all be singly filled
before they can be doubly occupied
Which elements do not fill the 4s subshell before the 3d subshell? - ANSWER-Copper
and chromium
Define the term ionic bond - ANSWER-The electrostatic attraction between oppositely
charged ions
What is the charge of an ion from group 1? - ANSWER-+1
What is the charge of an ion from group 2? - ANSWER-+2
What is the charge of an ion from group 6? - ANSWER--2
What is the charge of an ion from group 7? - ANSWER--1
Explain how atoms of sodium react with atoms of chlorine - ANSWER-Na loses its 2s1
electron gaining a +ve charge.
Cl gains an electron in the 3p subshell gaining a -ve charge.
The opposite charges attract to form NaCl
Why do ionic bonds have such high melting points? - ANSWER-Each +ve ion is
surrounded by 6 -ve ions and vice versa.
Strong electrostatic attraction in every direction.
Requires a large amount of energy to break
,State two factors that affect the strength of an ionic bond - ANSWER-Size of ion and
charge on ion
When can ionic substances conduct electricity? - ANSWER-When molten or in aqueous
solution
Describe the properties of ionic compounds - ANSWER-Conduct electricity when molten
or aqueous solution
High melting/boiling points
Usually soluble in water
Define the term covalent bond - ANSWER-A shared pair of electrons
Which metals lose electrons from the 4s subshell before the 3d subshell? - ANSWER-
Transition metals
Why do metals have such high melting points? - ANSWER-Strong force of attraction
between positive ions and delocalised electrons. This requires a large amount of energy
to overcome.
State the two factors that affect the strength of metallic bonding - ANSWER-Size of ion
Charge on ion
Explain why metals conduct electricity - ANSWER-The delocalised electrons 'carry'
charge. Current flows because of this.
Explain why metals conduct heat - ANSWER-Particles are paced tightly so kinetic
energy is passed from ion to ion. The delocalised electrons also enable heat to be
passed.
Explain why metals are ductile and malleable - ANSWER-The lattice structure allows
layers of metal ions to slide over each other without disrupting bonding
Explain how the charge on metal ions affects the strength of the metallic bond -
ANSWER-The larger the +ve charge the greater the attraction between the nucleus and
the delocalised electrons
Explain how the size of the metal ions affects the strength of the metallic bond -
ANSWER-The smaller the +ve ion the closer the nucleus is to the delocalised electrons
creating a greater attraction
Name the 3 forces between molecules - ANSWER-Van der Waals
Permanent dipole-dipole
Hydrogen bonds
, Order the 3 forces between molecules in order of strongest to weakest - ANSWER-
Hydrogen bonds
Permanent dipole-dipole
Van der Waals
How are Van der Waal's forces formed? - ANSWER-Electrons move to one side,
caused temporary dipole. This induces a temporary dipole in neighbouring molecules.
Attraction occurs between oppositely charged dipoles
In what molecules do Van der Waal's forces exist? - ANSWER-Non-polar molecules
How are permanent dipole-dipole forces formed? - ANSWER-Permanent dipole in one
molecule attracts oppositely charged permanent dipole in neighbouring molecule
In which molecules do permanent dipole-dipole forces exist? - ANSWER-Polar
molecules
Which elements must be present for hydrogen bonds to exist? - ANSWER-Hydrogen
and either nitrogen, oxygen or fluorine
What is meant by the term displacement? - ANSWER-When a more reactive element
takes the place of a less reactive element in a compound
State the equation for determining moles - ANSWER-Moles = mass ÷ relative atomic
mass (molar mass)
Define the term Avogadro's Constant - ANSWER-The number of atoms in a mole of a
given substance. Quoted as 6.02x10^23
Define the term relative atomic mass - ANSWER-The average mass of an atom of an
element relative to 1/12th the relative atomic mass of Carbon12
Define the term relative molecular mass - ANSWER-The average mass of a molecule
relative to 1/12th the relative atomic mass of Carbon12
What does this number represent? 6.02x10^23 - ANSWER-The number of particles in a
mole. Commonly called Avogadro's Constant
What is the equation for calculating % yield? - ANSWER-% yield = (actual yield ÷
theoretical yield) x 100
What groups are included in the 's' block of the periodic table? - ANSWER-Groups 1
and 2
What part of the periodic table is known as the 'd' block? - ANSWER-Transition metals
