Final answer:
The number of covalent bonds atoms are predicted to form is based on their need for electrons to reach an octet. Carbon forms four, tellurium and selenium two, nitrogen and phosphorus three, and bromine one. There can be exceptions to these predictions, especially for transition metals or in cases of expanded octets.
Step-by-step explanation:
Predicting the Number of Covalent Bonds Formed by Atoms
To predict how many covalent bonds are formed by each atom, we look at the number of valence electrons and how many additional electrons the atom needs to reach a stable octet. Here's the predicted number for each given atom:
- Carbon (C): With four valence electrons, carbon tends to form four covalent bonds.
- Tellurium (Te): Being in group 16, tellurium has six valence electrons and typically makes two covalent bonds to complete its octet.
- Nitrogen (N): Nitrogen has five valence electrons and tends to form three covalent bonds.
- Phosphorus (P): Also with five valence electrons like nitrogen, phosphorus often forms three covalent bonds but can sometimes form five due to its ability to expand its valence shell.
- Selenium (Se): Also in group 16 like tellurium, selenium forms two covalent bonds.
- Bromine (Br): As a group 17 element with seven valence electrons, bromine typically forms one covalent bond.
It is important to note that while these predictions are based on the octet rule, they are general guidelines and there can be exceptions, notably for molecules that do not follow this rule like those containing transition metals or are in environments where expanded octets are possible.