Atoms, Isotopes and the Periodic Table

Question 1

All substances are made of?

Answer 1

atoms

Question 2

What is an atom?

Answer 2

An atom is the smallest part of an element that can exist

Question 3

How many elements are there?

Answer 3

118

Question 4

List all the “things” found in an atom

Answer 4

1) nucleus (protons and neutrons)

2) electrons

Question 5

What is the nucleus?

Answer 5

It is a dense region in the middle of the atom composed of positive protons and neutral neutrons meaning it has a positive charge.
Almost the whole mass of the atom is concentrated in the nucleus

Question 6

What are electrons?

Answer 6

They orbit the nucleus in fixed energy levels

They are negatively charged and tiny

Question 7

Atoms have an overall charge of? and why?

Answer 7

0 - protons are positive and electrons are negative, and the number of protons and electrons in an atom are always equal.

Question 8

What is an element?

Answer 8

A substance made up of atoms that all have the same number of protons in their nucleus.

Question 9

What is an isotope?

Answer 9

Isotopes are different forms of the same element which have the same number of protons but a different number of neutrons

Question 10

What is a compound?

Answer 10

A compound is a substance formed from 2+ elements whose atoms are all held together by chemical bonds, When elements react, atoms combine with other atoms to form compounds

Question 11

What is a mixture?

Answer 11

A mixture consists of two or more elements or compounds not
chemically combined together. The chemical properties of each
substance in the mixture are unchanged.

Question 12

Diagrams of Dalton, Thompson, Chadwick, Bohr and Rutherford’s models

Answer 12

https://www.guyhowto.com/atomic-models-explained/

Question 13

Why was Dalton’s model discarded?

Answer 13

Thomson’s experiments with cathode ray tubes helped him to discover the electron. Dalton thought that atoms were indivisible particles, and Thomson’s discovery of the electron proved the existence of subatomic particles showing that atoms were not just empty spheres

Question 14

Why was Thomson’s model discarded?

Answer 14

Rutherford’s gold foil experiment proved the existence of a nucleus inside the atom, which the plum pudding model didn’t have, leading to it being discarded

Question 15

Why was Rutherford’s model discarded?

Answer 15

The main problem with Rutherford’s model was that he couldn’t explain why negatively charged electrons remain in orbit when they should instantly fall into the positively charged nucleus. This problem would be solved by Niels Bohr’s model leading to his being discarded

Question 16

Given the mass number: x, and the atomic number: y, how many electrons, protons and neutrons are in atom z

Answer 16

protons = y
electrons = y
neutrons = x - y

Question 17

What is an ion?

Answer 17

ions are charged particles due to the loss or gain of 1+ electrons

Question 18

Why are ions formed?

Answer 18

Ions are formed because atoms try to lose or gain electrons so that they can have a full outer shell. Atoms with full outer shells are very stable.

Question 19

When metals form ions they…

Answer 19

loose electrons from their outer shell to form positive ions

Question 20

When non-metals form ions they…

Answer 20

gain electrons into their outer shell to form negative ions

Question 21

Why do ions have charge?

Answer 21

The reason atoms don’t have charge is because protons are positive and electrons are negative, and the number of protons and electrons in an atom are always equal.
However, when atoms lose or gain electrons to try to have full outer shells, they no longer have equal numbers of protons and electrons and therefore will have an overall positive or negative charge

Question 22

Electronic configuration and structure for sodium?

Answer 22

https://in.pinterest.com/pin/858709853943204204/

Question 23

The periodic table is organised in…

Answer 23

ascending proton/atomic number

Question 24

The group number is…

Answer 24

the number of electrons in the outer shell

Question 25

what is the outer shell called

Answer 25

the valence shell

Question 26

The period number is…

Answer 26

the number of shells

Question 27

The table is called a periodic table because…

Answer 27

similar properties occur at regular intervals

Question 28

Elements in the same periodic table group have…

Answer 28

the same number of electrons in their outer shell giving them similar chemical properties

Question 29

Why are the electrons in the valence shell especially important?

Answer 29

Because they can engage in the sharing and exchange that is responsible for chemical reactions

Question 30

Chadwick? Time?

Answer 30

1932

He proved the existence of neutrons and therefore the model we used today has neutrons and protons in the nucleus.

Question 31

Why does chlorine not have a whole mass number?

Answer 31

The relative atomic mass of chlorine is 35.5 rather than a whole number. This is because chlorine has different isotopes

Question 32

Relative atomic mass formula?

Answer 32

total mass of all atoms/total number of atoms
total mass = abundance * mass number for every isotope
total number of atoms = sum of abundances