Metal atoms typically have few electrons in their outermost shell. To achieve a stable electronic configuration, they tend to lose these electrons, resulting in a positive charge. This process is driven by the octet rule, which states that atoms are most stable when they have eight electrons in their valence shell.
When a metal atom loses one or more electrons, it becomes a positively charged ion, or cation. This is because the number of protons in the nucleus (which is positively charged) remains the same, while the number of negatively charged electrons decreases. For example, sodium (Na) can lose one electron to form Na+, a common positively charged ion.
In summary, metal atoms are more likely to lose electrons and form positive ions (Option C) due to their tendency to seek a more stable electronic configuration.