The Periodic Table

Question 1

How did Mendeleev arrange the elements in his periodic table?

Answer 1

By relative atomic mass

Question 2

Explain why Mendeleev left gaps in his periodic table.

Answer 2

• To keep elements with similar properties in the same group
• This would help him predict the properties of undiscovered elements

Question 3

Why did some elements not always fit the way Mendeleev arranged the periodic table?

Answer 3

• In some cases, the relative atomic mass Mendeleev had was wrong
• This was due to the presence of isotopes

Question 4

Describe what is meant by the atomic number of an element.

Answer 4

The number of protons in the nucleus of an atom of a specific element

Question 5

Describe the structure of the modern periodic table.

Answer 5

• Elements are arranged in order of increasing atomic number, in rows called periods
• Elements with similar properties are placed in the same vertical columns called groups

Question 6

(Exam-style question)

Answer 6