CHAPTER 2 CHEMISTRY

Question 1

What is the change of state from solid to gas called?

Answer 1

sublimation

Question 2

What are the features of solids? (eg. arrangement, movement, forces, kinetic energy.)

Answer 2

-arrangement: particles are packed very closely together in an orderly arrangement.
- movement: particles vibrate about a fixed position and are not free to move.
- forces: particles are held together by strong forces.
- ke of particles: low.

Question 3

What are the features of liquids? (arrangement, movement, forces, kinetic energy.)

Answer 3

• arrangement: particles are packed close together but not in an orderly arrangement.
• movement: particles are able to slide over each other and move throughout the liquid.
• forces: particles are held together with weaker forces.
• ke of particles: higher.

Question 4

What are the features of gases? (arrangement, movement, forces, kinetic energy.)

Answer 4

• arrangement: particles are far apart in a random arrangement.
• movement: particles are free to move throughout the container or the space that the gas occupies.
• forces: force between particles is very weak or negligible.
• ke of particles: highest.

Question 5

Draw the heating curve and label the table

Answer 5

in diagram

Question 6

Draw the cooling curve and label the table

Answer 6

in diagram

Question 7

Describe what happens during melting or boiling

Answer 7

temperature remains constant during melting or boiling as the energy is being absorbed.

Question 8

Describe what happens during condensation or freezing

Answer 8

temperature remains constant during condensation and freezing as energy is being released.

Question 9

What is the atomic structure for proton?

Answer 9

• relative charge: +1
• relative mass: 1
• position: in the nucleus

Question 10

What is the atomic structure for neutron?

Answer 10

• relative charge: 0
• relative mass: 1
• position: in the nucleus

Question 11

What is the atomic structure for electron?

Answer 11

• relative charge: -1
• relative mass: 1/1840 = 0
• position: in electron shells

Question 12

What are the periodic table definitions?

Answer 12

• proton (atomic) number.
• nucleon (mass) number.
• isotopes.

Question 13

What is the definition of a proton (atomic) number?

Answer 13

the number of protons in the nucleus of an atom.

neutral atom: proton=electron

Question 14

What is the definition of a nucleon (mass) number

Answer 14

the number of neutrons and protons in the nucleus of an atom.

neutral atom: proton=electron

Question 15

How to find the number of atoms?

Answer 15

nucleon (mass) no. - proton (atomic) number.

Question 16

State the definition of isotopes

Answer 16

atoms of the same element with the same number of protons but different number of neutrons.

Question 17

What is the meaning of a group in the periodic table?

Answer 17

atoms of elements in the same group with the same number of valence electrons

Question 18

Is a period horizontal or vertical?

Answer 18

horizontal (━).

Question 18

Is a group vertical or horizontal?

Answer 18

vertical (⏐).

Question 19

What is the meaning of a period in the periodic table?

Answer 19

atoms of elements in the same period with the same number of electron shells

Question 20

Will there be more protons or electrons after forming positively charged ions?

Answer 20

no. of protons > no. of electrons

the no. of protons will never be equal to the no. of electrons.

Question 20

State the definition of positive ions

Answer 20

atoms of metals (Grp 1-13) that lose electrons to form positively charged ions to achieve a stable electronic configuration.

Question 21

Will there be more protons or electrons after forming positively charged ions?

Answer 21

no. of protons < no. of electrons

the no. of protons will never be equal to the no. of electrons.

Question 21

State the definition of negative ions

Answer 21

atoms of non metals (Grp 15-17) gain electrons to form negatively charged ions to achieve a stable electronic configuration.

Question 22

Does grp 18 elements lose or gain electrons?

Answer 22

grp 18 elements are chemically unreactive so they wont lose or gain electrons as their atoms already have a stable electronic configuration.