A) A metal forms a + charged ion, so D2+
B) A nonmetal forms a - charged ion, so A-
C) C2-
D) B+
I think that the question is not clear enough. Can you be more specific?
If your question was something like this: how many atoms of hydrogen can be around carbon, then the answer is 4. Carbon forms 4 bonds with other atoms.
Please note that carbon need not always form bonds to four atoms. A carbon could form a double bond with an oxygen and then two single bonds to hydrogen atoms. The carbon is only bonded to three atoms, but is forming a total of four bonds (1 double and 2 singles).
Biomolecules include large macromolecules (or polyanions) such as proteins, carbohydrates, lipids, and nucleic acids, as well as small molecules such as primary metabolites, secondary metabolites, and natural products. A more general name for this class of material is biological materials.
Examples of current electricity are like starting a car, turning on a light, cooking on an electric stove, watching TV, shaving with an electric razor, playing video games, using a phone, and charging a cell phone.
Hope These examples helped. :D
