Which term refers to the positively charged center of an atom?

• A. Neutron
• B. Nucleus
• C. Electron cloud
• D. Proton

Answer: (B)

Verified step by step guidance

1. Understand the structure of an atom, which consists of a nucleus at the center and an electron cloud surrounding it.
2. Recall that the nucleus contains protons and neutrons, where protons carry a positive charge and neutrons are neutral.
3. Recognize that electrons are negatively charged particles located in the electron cloud outside the nucleus.
4. Identify that the term referring to the positively charged center of an atom is the nucleus, because it contains the positively charged protons.
5. Note that 'neutron' refers to a neutral particle, 'electron cloud' refers to the region of negative charge, and 'proton' is a particle, not the entire center.