Which of the following best describes an ecosystem? a. all the living organisms in an area b. all the living organisms in an area and their physical surroundings c. a region with a distinct climate d. all the living organisms of the same species throughout the world

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons