On the basis of the structures, predict which of the following molecules are polar?
`H_2 O , CO_2 ,Be Cl_2 ,PH_3,CH_4 ,C Cl_4, SO_2.`

Explanation

To determine which of the given molecules are polar, we will analyze each molecule based on its structure and the electronegativity of its constituent atoms. A molecule is considered polar if it has a net dipole moment that is not equal to zero.

### Step-by-Step Solution:

1. **Water (H₂O)**:
- Structure: H₂O has a bent shape due to the two lone pairs on oxygen.
- Electronegativity: Oxygen is more electronegative than hydrogen.
- Dipole Moment: The dipole moments from the O-H bonds do not cancel out due to the bent shape, resulting in a net dipole moment.
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