Periodicity + Atomic Radii + Ionisation Energy and Electronegativity

Question 1

What are four different characteristics that change going up and down a group or across a period?

Answer 1

1) Atomic Radius
2) Ionic Radius
3) Melting Point
4)Electrical conductivity

Question 2

Which way is a period?

Answer 2

Across the table

Question 3

What is atomic radius?

Answer 3

basically the radius of the atom. the distance from the inside nucleus and the outer electrons,

Question 4

How does atomic radius change as you go down a group?

Answer 4

Atomic radius increases. The lowest elements have the longest atomic radii

Question 5

How does ionic radius change as you go down a group?

Answer 5

Ionic radius increases. The lowest elements have the widest atomic radii

Question 6

Why do atomic radius and ionic radius change as you go down a group?

Answer 6

Elements lower down have more electrons → More electrons need more shells to put them in → The more shells an element has, the wider it is → The longer the distance from the middle to the edge → a longer radius

Question 7

How does atomic radius change as you do across a period?

Answer 7

Atomic radius decreases

Question 8

How does ionic radius change as you go across a period?

Answer 8

Ionic radius decreases

Question 9

Why do atomic radius and ionic radius change as you go across a period

Answer 9

elements further to the right have more protons → protons have a positive charge → more protons means more positive charge → more positive charge in the middle means more pulling in of the outside negative electrons towards the middle → so electrons are closer to the middle → the distance from the middle to the outside electrons is smaller → a smaller atomic radius
RADIUS ONLY INCREASES WHEN YOU ADD A NEW ELECTRON SHELL, NOT WHEN YOU ADD MORE ELECTRONS TO AN EXISTING SHELL

Question 10

What two characteristics have the same periodic trends?

Answer 10

Atomic Radius and Ionic Radius. Both increase in atomic radius as you go down a group and decrease in atomic radius as you move along a group

Question 11

How does atomic radius periodic change from neutral atoms to ions?

Answer 11

it doesn’t. the particle further right with more protons will have more pull and a smaller atomic radius. The particles further down with more electrons will have more shells and so a larger atomic radius

Question 12

What does isoelectronic mean?

Answer 12

two or more atoms or ions with the same number and arrangement of electrons

Question 13

What process is necessary to melt a substance?

Answer 13

melting a substance requires adding enough energy to overcome the attractive forces holding the solid structure together

Question 14

What does a high melting point mean?

Answer 14

it means that the substance has strong attractive forces holding its particles together

Question 15

What kind of melting point do non-metals usually have?

Answer 15

non-metals generally have a lower melting point than metals because they are held together by a weaker London dispersion force

Question 15

What kind of melting point do metals usually have and why?

Answer 15

metals generally have a high melting point because they are held together by strong metallic bonds that take a lot of energy to break

Question 16

How does the melting point of metals correspond to their state at room temperature?

Answer 16

because metals typically have a high melting point, the vast majority of metals are solid at toom temperature because their melting point is higher than room temperature

Question 17

How does the melting point of non-metals correspond to their state at room temperature?

Answer 17

because non-metals typically have a low melting point, the vast majority of non-metals are gaseous at room temperature, because their melting point (and boiling points) are lower than room temperature

Question 18

What are some common metals?

Answer 18

• iron
• lead
• aluminium
• Silver
• calcium
• sodium
• copper
• mercury
• gold

Question 19

WHy does the melting point change across a period?

Answer 19

elements further to the right have more free electrons in their valence shells → electrons are negatively charged particles → more negatively charged particles → more attraction → more strength to the metallic bonds that make up the metal substances → stronger attractive forces holding the substance together → harder to break the bonds in the substance → higher metling point

Question 20

How does melting point change across a period?

Answer 20

There are no real patterns. Metals held by strong metallic forces will GENERALLY have higher melting points that non-metals held together by weak London dispersion forces

Question 21

Why do giant covalent structures structures have a high melting point?has the highest melting points and why?

Answer 21

elements with a giant covalent structure are held together by many covalent bonds. Each atom of the element is covalently bonded to other atoms in their immediate vicinity. The number and strength of the bonds in the structure mean that it requires lots of energy to break apart the solid structure of the substance. An example is silicon.

Question 22

Which metal is an exception to the “solid at room temperature” trend?

Answer 22

mercury

Question 23

Which non-metal has a higher melting point than the metal sodium?

Answer 23

the non-metal sulfur has a higher melting point than the metal sodium

Question 24

What is electrical conductivity?

Answer 24

the ability of a substance to carry an electric current since electricity is the flow of electrons

Question 25

What should you consider when figuring out how conductive a substance is?

Answer 25

electrons to move?

Question 26

What is the electrical conductivity of metals?

Answer 26

metals have a high electrical conductivity

Question 27

Why do metals have a the level of electrical conductivity that they do?

Answer 27

metals are held together by metallic bonds → metallic bonds have delocalised electrons, that float freely among the atoms of the substance → more electron freedom → more flow of electricity → more flow of electricity means higher electrical conductivity

Question 28

What is the electrical conductivity of nonmetals?

Answer 28

Nonmetals tend to have low electrical conductivity

Question 29

Why do nonmetals have the electrical conductivity that they do?

Answer 29

nonmetals tend to form covalent bonds (some exist as monatomic atoms, basically lone and without any bonds) → electrons still move around, but they’re stuck in the space between atoms instead of moving around freely in the substance → less freedom of electrons → less flow of electricity → low electrical conductivity

Question 30

What are delocalised electrons?

Answer 30

electrons that float freely among the atoms of the substance

Question 31

What side of the periodic table are metals in?

Answer 31

the left and middle mostly, except for hydrogen

Question 32

What side of the periodic table are nonmetals in?

Answer 32

the right mostly + hydrog

Answer 33

picometers

Question 34

Do semimetals behave like metals or nonmetals?

Answer 34

both. sometimes like metal and sometimes like nonmetals

Question 35

What kind of conductivity do semimetals have?

Answer 35

they have medium electrical conductivity

Question 36

How do you determine which element has a larger or smaller atomic radius if they are in the same period?

Answer 36

atomic radius decreases across a period → Basically the further you move right, the smaller the atomic radius is → The elements closest to the left will have the largest atomic radius + the elements closest to the right will have the smallest atomic radius

Question 37

What is periodicity?

Answer 37

trends and patterns found in the periodic table