periodic table

How are elements arranged in the modern periodic table?

in order of increasing atomic number?

what is a group in the periodic table?

a vertical column of elements with similar chemical properties (same number of electrons in their outer shell)

What is a period in the periodic table?

Horizontal row of elements where the period number shows the number of electron shells?

What does the group number tell you about an element?

the number of electrons in the outer shell

who developed the early modern periodic table by leaving gaps for undiscovered elements?

Dmiri mendeleev (1969)

are periodic tables arranged elements by atomic weight. Why did this cause problems, and how was it fixed?

Some electrons were in the wrong group due to similar properties not aligning it was fixed by ordering by atomic number instead.

Name the elements in group 1

The alkaline metals (lithium, sodium, potassium, rubidium, caesium, francium.)

Name the elements in group 7

The halogens (fluorine, chlorine, bromine, iodine, astatine).

Name the elements in group 0

The noble gases (helium, neon, organ, krypton, xenon, radon).

Where are metals and nonmetals generally located in the periodic table?

Metals are on the left and centre; nonmetals are on the right (with a zigzag line them)