U1L1

The number of elements in Mendeleevas periodic table is ….. elements

• 92
• 118
• 76
• 67

The scientist who left vacancies in his table to be filled with suitable discovered elements in future is ….

• Moseley
• Rutherford
• Bohr
• Mendeleev

Mendeleev classified the elements of each group into …. sub-groups

• 2
• 3
• 4
• 5

The nucleus of the atom contains …..

• positive electrons
• negative electrons
• negative protons
• positive protons

The scientist, who discovered that the nucleus of atom contains positively charged protons is ….

• Bohr
• Mendeleev
• Rutherford
• Moseley

The scientist ….. had discovered the main energy levels

• Moseley
• Bohr
• Hofman
• Mendeleev

the number of energy levels in the heaviest known atom reaches …. Levels till now

• 5
• 7
• 8
• 10

The number of known elements in the modern periodic table till now is ….

• 216
• 118
• 316
• 16

The number of elements which exist in nature is …..

• 29
• 118
• 92
• 102

The modern periodic table consists of …. horizontal periods

• 7
• 10
• 14
• 18