Chemistry

Question 1

Subatomic Particles

Answer 1

• Protons
• Neutrons
• Electrons

Question 2

Why is helium in group 18?

Answer 2

Helium is in group 18 becuase like all the other elements in group 18, helium has a full valence shell.

Question 3

Neutron’s Charge?

Answer 3

No charge

Question 4

Rutherford’s Model?

Answer 4

His model of the atom had a nucleus with protons in it and the electrons were just circling it. It had no neutrons. The electrons were like the seeds in a watermelon.

Question 5

How did Borh change Rutherford’s model?

Answer 5

Bohr modified the Rutherford modelby requiring that the electrons move in orbits of fixed size and energy.

Question 6

Si

Answer 6

Silicon

Question 7

Fe

Answer 7

Iron

Question 8

Al

Answer 8

Aluminum

Question 9

Ionic compounds

Answer 9

Pure substances consisting of at least one metal and one non metal

Question 10

Molecular Compound

Answer 10

Consists of at least two non metals, no metals.

Question 11

Naming ionic compound

Answer 11

Just add -ide. In an ionic compound, metals are always written first.

Question 12

Naming molecular compound.

Answer 12

1. Add a prefix to represent the atoms of each element in the compound. The prefix mono- is only used with the second element.
2. Add -ide to the second element.

Question 13

Atomic number

Answer 13

Number of Protons in the atom of that element.

Question 14

Covalent bond

Answer 14

A chemical bond in which the valence electrons of one or more atoms are shared. This is how a molecular compound is formed.

Question 15

Valence electrons

Answer 15

The electrons in the outer most shells of the atom.

Question 16

Ions

Answer 16

Charged atoms or molecules that form when atoms lose or gain electrons.

Question 17

Isotope

Answer 17

Isotopes aremembers of a family of an element that all have the same number of protons but different numbers of neutrons. Isotopes have a different atomic mass from the periodic table.

Question 18

Atoms

Answer 18

Smallest unit of matter.

Question 19

Cation

Answer 19

Positively charged ion

Question 20

Anion

Answer 20

Negatively charged ion

Question 21

Who discovered the electron?

Answer 21

J.J Thomson

Question 22

Who discovered the proton?

Answer 22

E. Rutherford

Question 23

Who discovered the neutron?

Answer 23

James Chadwick

Question 24

Molecule

Answer 24

A molecule is an electrically neutral group of two (or more) atoms chemically bonded together.

Question 25

Why are element in group 18 stable?

Answer 25

They are stable becuase they have a full valence shell.

Question 26

Why is group 18 special?

Answer 26

Group 18 is special becuase the elements in that group have a full valence shell, they do not need more electrons.

Question 27

Pb

Answer 27

Lead