1. Which of the following molecules are polar based on shape? Mark all that apply Carbon Dioxide (CO_(2)) Water (H_(2)O) Ammonia (NH_(3)) Methane (CH_(4)) Formaldehyde (CH_(3)O)

To determine which molecules are polar based on their shape, we need to consider the molecular geometry and the distribution of electron density around the central atom.

1. Carbon Dioxide (CO2): CO2 has a linear molecular geometry with two oxygen atoms symmetrically arranged around the central carbon atom. The oxygen atoms have the same electronegativity, so the dipole moments cancel out, making CO2 a nonpolar molecule.

2. Water (H2O): Water has a bent molecular geometry with two hydrogen atoms bonded to the oxygen atom. The oxygen atom is more electronegative than the hydrogen atoms, creating a dipole moment. The bent shape of the molecule prevents the dipole moments from canceling out, making water a polar molecule.

3. Ammonia (NH3): Ammonia has a trigonal pyramidal molecular geometry with three hydrogen atoms bonded to the nitrogen atom. The nitrogen atom is more electronegative than the hydrogen atoms, creating a dipole moment. The trigonal pyramidal shape of the molecule prevents the dipole moments from canceling out, making ammonia a polar molecule.

4. Methane (CH4): Methane has a tetrahedral molecular geometry with four hydrogen atoms symmetrically arranged around the central carbon atom. The hydrogen atoms have the same electronegativity, so the dipole moments cancel out, making methane a nonpolar molecule.

5. Formaldehyde (CH3O): Formaldehyde has a trigonal planar molecular geometry with two hydrogen atoms and one oxygen atom bonded to the central carbon atom. The oxygen atom is more electronegative than the hydrogen atoms, creating a dipole moment. The trigonal planar shape of the molecule prevents the dipole moments from canceling out, making formaldehyde a polar molecule.

Based on the above analysis, the polar molecules among the given options are:
- Water (H2O)
- Ammonia (NH3)
- Formaldehyde (CH3O)