Year 8 Science History of the Periodic Table

Year 8 Namirembe and Year 8 Rubaga Science

Timeline

Producing a ___ is a goal for showing the development of the periodic table.

Dmitri Mendeleev

It is important to explain the role of ___ in developing the periodic table.

Vertical columns

Elements in ___ are known as groups.

Periods

Horizontal rows in the periodic table are called ___.

Group number

The ___ shows the amount of electrons in the outermost shell.

Outermost shell

The group number indicates how many electrons are in the ___.

More reactive

In group 1 the elements become ___ as you move down the group.

Decreases

In group 7 the reactivity ___ as you move down the group.

Silicon

The element found in group 4 and period 3 is ___.

Iodine

The element found in group 7 and period 5 is ___.

Helium

The element found in group 0 and period 1 is ___.

Calcium

The element found in group 2 and period 4 is ___.

Twelve

The element magnesium has ___ electrons.

Group 2

Magnesium is in ___ because it has 2 electrons in its outer shell.

Zinc

One element Mendeleev placed in group 2 that is not there today is ___.

Cadmium

Along with zinc Mendeleev incorrectly placed ___ in group 2.

Gaps

Mendeleev left ___ in his periodic table for undiscovered elements.

Atomic number

Elements in today's periodic table are arranged in order of ___.

Johann Dobereiner

In 1817 ___ proposed the Law of Triads.

Law of Triads

The ___ involved placing elements into groups of three based on appearance.

Three

The Law of Triads placed elements into groups of ___.

John Newlands

In 1864 ___ proposed the Law of Octaves.

Law of Octaves

The ___ suggested that every eighth element was similar.

Atomic mass

Newlands and Mendeleev both originally arranged elements by ___.

Eight

Newlands suggested elements were similar to the element ___ places further on.

1869

Dmitri Mendeleev published his version of the periodic table in ___.

Switch elements

Mendeleev was willing to ___ around to ensure they fit chemically.

Group numbers

One difference in Newlands' table is that it doesn't have ___.

Different order

A key difference between old and new tables is that elements are in a ___.

Groups

In the modern periodic table elements in the same ___ have similar properties.

H

The symbol for Hydrogen is ___.

Li

The symbol for Lithium is ___.

Be

The symbol for Beryllium is ___.

B

The symbol for Boron is ___.

C

The symbol for Carbon is ___.

N

The symbol for Nitrogen is ___.

O

The symbol for Oxygen is ___.

F

The symbol for Fluorine is ___.

Na

The symbol for Sodium is ___.

Mg

The symbol for Magnesium is ___.

Al

The symbol for Aluminum is ___.

Si

The symbol for Silicon is ___.

P

The symbol for Phosphorus is ___.

S

The symbol for Sulfur is ___.

K

The symbol for Potassium is ___.

Fe

The symbol for Iron is ___.

Cu

The symbol for Copper is ___.

Ag

The symbol for Silver is ___.