Which period of the periodic table contains maximum number of elements?

Options

A. 2nd
B. 6th
C. 4 th
D. 5 th

Explanation

To determine which period of the periodic table contains the maximum number of elements, we can follow these steps:

### Step 1: Understand the Structure of the Periodic Table
The periodic table is organized into periods (horizontal rows) and groups (vertical columns). Each period corresponds to the filling of electron shells.

### Step 2: List the Number of Elements in Each Period
We can list the number of elements in each of the seven periods:
- **Period 1**: 2 elements (H, He)
- **Period 2**: 8 elements (Li, Be, B, C, N, O, F, Ne)
- **Period 3**: 8 elements (Na, Mg, Al, Si, P, S, Cl, Ar)
- **Period 4**: 18 elements (K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Kr)
- **Period 5**: 18 elements (Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe)
- **Period 6**: 32 elements (Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, Rn)
- **Period 7**: 32 elements (Fr, Ra, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, Nh, Fl, Mc, Lv, Ts, Og)

### Step 3: Identify the Period with the Maximum Number of Elements
From the list above, we can see:
- Period 1 has 2 elements
- Period 2 has 8 elements
- Period 3 has 8 elements
- Period 4 has 18 elements
- Period 5 has 18 elements
- Period 6 has 32 elements
- Period 7 has 32 elements

The sixth and seventh periods both contain 32 elements, which is the highest number of elements in any period.

### Step 4: Conclusion
Thus, the periods that contain the maximum number of elements are the **sixth and seventh periods**, each with 32 elements.

### Final Answer
The sixth and seventh periods contain the maximum number of elements (32 elements each).

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