Exercises U1 L2

The modern periodic table consists of ................... main blocks.

• 2

• 4

• 5

• 8

The elements which occupy the middle block (d) in the periodic table are called ................... elements.

• transition

• alkali

• acidic

• noble

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

• second

• third

• fourth

• fifth

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

• number of protons inside the nucleus.

• atomic number.

• number of energy levels.

• number of electrons in the outermost energy level.

The number of negative electrons in the atom in its normal state equals ........................

• the number of protons.

• the number of neutrons.

• twice the number of protons.

• half the number of neutrons.

The element which is located in period (3) and group (3A) is .......................

• ₁₃Al

• ₅B

• ₁₁Na

• ₁₅P

The atomic number of the element that is located in period (4) and group (2A) is .......................

• 4

• 18

• 12

• 20

The element whose atomic number (18) is ...................

• transition element

• inert gas

• metallic element

• halogen element

The atomic number of the element that exists in group (7A) and period (2) is .....................

• 12

• 9

• 7

• 17

The element (₁₂X) is located in ......................... of the periodic table.

• period (2) and group (2A)

• period (3) and group (2A)

• period (2) and group (3A)

• period (3) and group (4A)