The question is........Suppose one large atom bonds with one small atom. Predict whether the properties of the new molecule will be the same as the large atom, the same as the small atom, or different from both atoms.

Why would the molecule behave chemically like the component atoms? Chemical behavior depends on the filling or emptying of outer electron shells. If that changes all bets are off.

Is water H2O like hydrogen H2 or Oxygen O2 ?

To predict the properties of a new molecule formed when a large atom bonds with a small atom, we need to consider the concept of chemical bonding and the differences in atomic size.

When atoms bond, they share, give away, or accept electrons to achieve a stable electron configuration. This process can result in the formation of a molecule with properties that may be different from either of the individual atoms involved.

In the case of a large atom bonding with a small atom, such as in an ionic or covalent bond, the properties of the new molecule will be different from both atoms. Here's why:

1. Ionic Bonding: In an ionic bond, which typically occurs between a metal and a non-metal, the large atom (metal) loses one or more electrons and forms a positive ion (cation), while the small atom (non-metal) gains one or more electrons and forms a negative ion (anion). The oppositely charged ions attract each other, creating a bond. The resulting molecule, known as an ionic compound, usually has different properties, such as higher melting and boiling points, conductivity when dissolved in water, and crystal lattice structure, compared to the individual atoms.

2. Covalent Bonding: In a covalent bond, which typically occurs between non-metal atoms, both the large and small atoms share electrons. The sharing of electrons allows both atoms to achieve a more stable electron configuration. The resulting molecule, known as a covalent compound, will have properties that can differ from both atoms, depending on the nature and strength of the bond. Covalent compounds can have various properties, such as low melting and boiling points, poor conductivity, and a diverse range of physical and chemical characteristics.

In summary, when a large atom bonds with a small atom, the properties of the new molecule will be different from both atoms due to the change in electron arrangement and the type of bonding involved (ionic or covalent). It is important to consider the specific elements involved and the nature of the bonding to make more accurate predictions about the properties of the resulting molecule.