Which of the following statement `(s)` is`//`are correct ?

Options

A. The last member of the `7th` period of the periodic table will have atomic number `118` if observed.
B. All the transition elements are metals and paramagnetic .
C. The maximum number of elements are present in the `5th` period of the periodic table.
D. Every period of the periodic table starts with a member of alkali group.

Explanation

To determine which of the statements are correct, we will analyze each statement one by one.

### Step 1: Analyze the First Statement
**Statement A:** The last member of the seventh period in the periodic table will have atomic number 118 if observed.

- The seventh period of the periodic table can accommodate a maximum of 32 elements.
- The last element in this period would be the one with atomic number 118.
- The electronic configuration of this element would be:
- Radon (Rn, atomic number 86) + 32 = 118.
- The filling order of orbitals is: 7s, 5f, 6d, and 7p.
- The last electron will fill the 7p orbital, resulting in a configuration of 7p6.
- Therefore, this statement is **correct**.

### Step 2: Analyze the Second Statement
**Statement B:** All the transition elements are metals and paramagnetic.

- Transition elements are found in the d-block of the periodic table and are generally metals.
- Most transition metals have unpaired electrons, which makes them paramagnetic.
- The exceptions are Zn, Cd, and Hg, which are not paramagnetic due to having a full d-subshell.
- However, since the statement does not specify exceptions, we can consider it **correct** in a general sense.

### Step 3: Analyze the Third Statement
**Statement C:** The maximum number of elements are present in the fifth period of the periodic table.

- The fifth period contains:
- 2 electrons from 5s,
- 10 electrons from 4d,
- 6 electrons from 5p.
- Total = 2 + 10 + 6 = 18 elements.
- However, the sixth and seventh periods can each accommodate 32 elements.
- Thus, this statement is **incorrect**.

### Step 4: Analyze the Fourth Statement
**Statement D:** Every period of the periodic table starts with a member of the alkali group.

- The first period contains only Hydrogen (H) and Helium (He).
- Hydrogen is not an alkali metal; it is a non-metal.
- Therefore, this statement is **incorrect**.

### Conclusion
- **Correct Statements:** A and B.
- **Incorrect Statements:** C and D.

### Final Answer
The correct statements are A and B.

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