Chapter 5- The periodic table

Question 1

Define the periodic law.

Answer 1

States that the elements are arranged in increasing atomic number and shows periodic change in their properties.

Question 2

Define valence electrons.

Answer 2

The electrons in the outermost energy level of the atom that will determine how an atom will react in a chemical reaction.

Question 3

Define the ionization energy.

Answer 3

The amount of energy released per mole when an elements atoms gain an electron.

Question 4

Define an ion.

Answer 4

Any charge particle.

charge is created when a neutral atom gains or loses electrons

Question 5

Define the octet rule.

Answer 5

Atoms gain, lose or share electrons to achieve the stable electronic configuration of the noble gases.

Question 6

Define the term electron affinity.

Answer 6

The amount of energy released per mole when an elements atoms gain an electron.

Question 7

Define the term electronegativity.

Answer 7

A measure of the tendency of an atom to attract a bonding pair of electrons towards itself.

Question 8

How are elements in the periodic table arranged?

Answer 8

Elements are arranged in groups according to their chemical and physical properties.

Question 9

Why are certain elements arranged in the same periods or groups?

Answer 9

They are arranged in the same periods due to the common energy levels that their electrons fill.
Elements are arrange in the same groups due to same amount of valence electrons.

Question 10

What is an alloy?

Answer 10

A metal made by combining two or more metallic elements.

Question 11

Mention the physical characteristics of a metal.

Answer 11

• shine, malleable, high density.
• good conductors of electricity.
• good conductors of heat.
• high melting and boiling points.
• a few has magnetic properties.

Question 12

Mentions the chemical characteristics of metals.

Answer 12

• release H2 when it reacts with an acid.
• Forms oxides when it reacts with O2
  (base/alkali- pH above 7)

Question 13

Mentions the physical characteristics of non-metals.

Answer 13

• many are gasses.
• low density.
• forms brittle solids.
• only carbon in the form of graphite are conductors.
  non-metals are mostly insulators.

Question 14

Mention the chemical characteristics of non-metals.

Answer 14

• do not react with acids.
• usually forms dioxides when reacting with O2
  (acid- pH below 7)

Question 15

Mention the physical characteristics of metalloids.

Answer 15

• shine, fairly dense.

Question 16

Mention the chemical characteristics of metalloids.

Answer 16

• do not react with acids.
• conduct electricity at high temperatures( useful to the computer industry)
• insulators at low temperatures.

Question 17

What are materials that can conduct electricity and heat?

Answer 17

Electrical conductors can conduct electricity.

Usually conductors of electricity are also conductors of heat - thermal conductors.

Question 18

Which substances are called ferromagnetic material?

Answer 18

Iron, Nickel and Cobalt are magnetic substances.

Question 19

What is the aim of the elements?

Answer 19

All elements aim to have the stable electrons configuration that the noble gasses have.

Question 20

Which is the most reactive metal?

Answer 20

Francium

Question 21

Why would fluorine attract an electron to its self more easily?

Answer 21

Fluorine( group 17) would need just one more electron for it to have a full energy level and since fluorine is the smallest atom in group 17 the protons would be able to exert a stronger force over an electron than the protons in chlorine.