periodic table

Question 1

Are all elements in the Periodic Table naturally occurring?

Answer 1

No, elements up to uranium (92U) are naturally occurring; elements past uranium are synthesized

Transuranium elements are radioactive.

Question 2

How did Mendeleev organize the elements?

Answer 2

According to similar chemical properties and in order of atomic mass

Left gaps for undiscovered elements.

Question 3

What are groups in the Periodic Table?

Answer 3

Vertical columns numbered 1 - 18 with similar chemical properties

React in similar ways and have the same number of valence electrons.

Question 4

What are periods in the Periodic Table?

Answer 4

Horizontal rows numbered 1 – 7 with properties that increase or decrease across the period

Have the same number of electron shells.

Question 5

What is the link between an element’s position and its electron configuration?

Answer 5

Elements in the same group have the same number of valence electrons

Elements in the same period have the same number of electron shells.

Question 6

How many valence electrons do alkali metals have?

Answer 6

1 valence electron

Question 7

How many valence electrons do alkaline earth metals have?

Answer 7

2 valence electrons

Question 8

How many valence electrons do halogens have?

Answer 8

7 valence electrons

Question 9

How many valence electrons do noble gases have?

Answer 9

8 valence electrons

Question 10

What are transition metals?

Answer 10

Metals in the middle of the periodic table, usually hard and dense

Often exist in multiple forms.

Question 11

What are lanthanides and actinides?

Answer 11

Elements that fit into the periodic table next to the transition metals, most are synthetic

Many are radioactive and/or unstable.

Question 12

What are metalloids?

Answer 12

7 elements with properties of both metals and non-metals

They are semiconductors.