Periodic Table And Energy Flashcards
(26 cards)
What are the vertical column in the periodic table called?
Groups
They have same number of outer shell electrons and similar properties.
What are the horizontal rows in a periodic table called?
Periods
The number of the period gives the number of the highest energy electron shells in an element’s atoms.
What does ionisation energy measure?
How easily an atom loses electrons to form positive ions.
Definition the first ionisation energy?
The energy required to remove one electron from each atom in one mole of gaseous atoms of an element to form one moles of gaseous 1+ ions.
What factors affect ionisation energy?
Atomic radius
Nuclear charge
Electron shielding
How does atomic radius affect ionisation energy?
The greater the distance between the nucleus and the outer electrons, the less the nucleus attraction. The force of attraction fall
How does nuclear charge affect ionisation energy?
The more protons there are in the nucleus of an atom, the greater the attraction, between the nucleus and the outer electrons.
How does electron shielding?
Electrons are negatively charged and so inner-shell electrons repel outer-she’ll electrons. This repulsion, called the shielding effect, reduces the attraction between the nucleus and the outer electrons.
What is an ionised gas called?
Plasma
What is the second ionisation energy definition
The energy required to remove one electron from ion in one mole of gaseous 1+ ions of an element to form one mole of gaseous 2+ ions.
What is the trend down a group in first ionisation energies?
Atomic radius increases
More inner shells so shielding increases
Nuclear attraction on outer electrons decreases
First ionisation energy decreases.
What are the trends across a period in first ionisation energies?
Nuclear charge increases Same shell; similar shielding Nuclear attraction increases Atomic radius decreases First ionisation energy increases
Why is there a fall in the first ionisation energies from beryllium to boron?
2p sub shell is beginning to be filled
What is one constant property of metals?
Their ability to conduct electricity.
What is a cation?
A positively charged ion with fewer electrons than protons.
What is an anion?
A negatively charged ion with more electrons than protons
Name some properties of metals
Strong metallic bonds-attraction between positive ions and delocalised electrons.
High electrical conductivity
High melting and boiling points
Are metals soluble?
No
What are typical properties of substances with giant covalent structures?
Very strong covalent bonds so are very stable and hard to break down.
What are the melting and boiling points of giant covalent lattices?
They are very high- this is because covalent bonds are strong. High temperatures are necessary to provide the large quantity of energy to break the bonds.
How soluble are giant covalent lattices?
Insoluble in almost all solvents. The covalent bonds are too strong to be broken by interactions with solvents.
Are giant covalent lattices conductors of electricity?
They already mostly non-conductors, however graphemes and graphite are exceptions.
What is the trend in melting points across the period?
Melting point increases from group 1 to group 14.
There is a sharp decrease between group 14 and group 15 this is because of a change from giant to simple molecular structures.
The melting points are low from group 15 to group 18.
What are the characteristics of group 2 elements?
Metals
Reactive
Often found as a compound rather than pure
