How is the Periodic Table Arranged

Question 1

What is the Periodic Table?

Answer 1

A table where elements are organized by increasing atomic numbers (number of protons).

Question 2

How was the periodic table originally organized?

Answer 2

In the late 1800’s, Dmitri Mendeleev devised the first period table based on atomic mass. However some elements were out of order.

Question 3

How is the periodic table organized now?

Answer 3

In 1913, Henry G.J. Moseley arranged the elements by atomic number and it is still used today.

Question 4

Who created the first periodic table?

Answer 4

Dmitri Mendeleev

Question 5

Who created the periodic table we used today?

Answer 5

Henry G.J. Moseley

Question 6

How is the periodic table arranged?

Answer 6

By groups and periods.

Question 7

What are “groups” on the periodic table?

Answer 7

Groups are vertical columns of elements with similar properties. Groups are numbered 1-18.

Question 8

How are periodic table “groups” numbered?

Answer 8

1-18

Question 9

What are “periods” on the periodic table?

Answer 9

Periods are horizontal rows of elements that contain increasing numbers of protons and electrons. Periods are numbered 1-7.

Question 10

How are periodic table “periods” numbered?

Answer 10

1-7

Question 11

How do elements within a “group” compare to each other?

Answer 11

Elements in the same group have the same number of electrons in their outer energy level.

Question 12

How do elements within a “period” compare to each other?

Answer 12

All elements in a row have the same number of electron shells. Each next element in a period has one more proton than its predecessor. Each horizontal row in the periodic table ends when an outer energy level is filled.

Question 13

How do energy levels and valance electrons relate to the periodic table?

Answer 13

The highest energy level number (1 through 7) for the electrons in an atom corresponds to the period (or row) in the periodic table to which that atom belongs. Because there are 7 periods in the table, there are 7 energy levels. For example, hydrogen (H) is int eh first period, so it has only one energy level.

Question 14

What is an Electron Dot Diagram?

Answer 14

Uses the element symbol and dots to represent outer energy level electrons.

Question 15

What is the max electrons that can be on an outer energy level?

Answer 15

8 electrons. The exceptions are Hydrogen and Helium, which only have a max of 2.

Question 16

What are the max electrons on the outer energy level for Hydrogen and Helium?

Answer 16

2

Question 17

What makes an element radioactive?

Answer 17

The rays and particles emitted by an unstable nucleus. This happens when the atoms of an element have extra neutrons or protons, which creates extra energy in the nucleus and causes the atom to become unbalances or unstable.

Question 18

What are three of the main elements that make up the human body?

Answer 18

Hydrogen, Oxygen, Carbon and Nitrogen. Nitrogen is the least.

Question 19

What percentage of the human body is Hydrogen?

Answer 19

9.5%

Question 20

What percentage of the human body is Carbon?

Answer 20

18.5%

Question 21

What percentage of the human body is Oxygen?

Answer 21

65%

Question 22

What percentage of the human body is Nitrogen?

Answer 22

3.2%