Question

atoms consist of a positively charged center called a(n) __________. *
proton
neutron
electron
nucleus
the negative charged particles outside the nucleus of an atom are __________. *
extracellular material
electrons
neutrons
quarks

Explanation:

1. An atom has a positively - charged center called the nucleus which contains protons and neutrons. Protons are positively charged particles within the nucleus, neutrons are neutral, and electrons are outside the nucleus.
2. Electrons are the negatively - charged particles that orbit outside the nucleus of an atom. Extracellular material is related to cells in biology and not to atomic structure, neutrons are neutral, and quarks are sub - particles that make up protons and neutrons.

Answer:

1. D. nucleus
2. B. electrons