Attempts of Elements classification

The nucleus of the atom contains.......

• positive electrons

• positive protons

• negative electrons

• negative protons

Each main energy level contains a definite number of energy

• Sublevels
• levels

• periods

• groups

Moseley put.........and........below the periodic table

• inert gases - lanthanides

• S_block - p_block

• lanthanides - actinides

• D_block - F_block

The transition elements start to appear from the beginning of the.........period

• fourth
• third

• fifth

• second

There is a question that says --Elements of D_block are arranged in......groups--

sally answered it --2--

mariam answered it --5--

malak answered it --6--

you answered it --10--

who answered it correct?

• you

• mariam

• sally

• malak

Nobel gases are located in group.......

• zero
• 12

• 6

• 17

Elements of group (6A) in the periodic table have the same number of

• proton inside the nucleus

• energy levels around the nucleus

• neutrons inside the nucleus

• electrons in the outermost energy levels

The number of electrons of period (4) is ......... the number of elements of elements of period (3)

• equal to

• less than

• more than

• half

The element whose atomic number (18) is

• transition element

• metalic element

• halogen element

• inert gas

Elements of the period in the modern periodic table have the number of........

• protons inside the nucleus

• atomic number

• electrons in the outermost energy level

• energy levels around the nucleus