Question

A)
The nucleus is the dense center of the atom composed of protons and neutrons. Surrounding the nucleus is an electron cloud composed of electrons.
B)
The nucleus is the dense center of the atom composed of electrons and neutrons. Surrounding the nucleus is an electron cloud composed of protons.
C
The electron cloud is the dense center of the atom composed of electrons. Surrounding the electron cloud is a nucleus composed of protons and neutrons.
D
The electron cloud is the dense center of the atom composed of protons and neutrons. Surrounding the ele

Answer 1

what is the strucher of a atop^^^^^^^^

Answer 2

An atom is made up of an electron cloud surrounding the nucleus. The Nucleus is made up of Protons and Neutrons EXCEPT for a Hydrogen atom - it has one Proton in its nucleus and one Electron. And except for rare isotopes, such as Deuterium and Tritium, the normal hydrogen atom has NO neutrons.
The number of Protons in the Nucleus determines what element the atom is. Although a Neutral Atom usually has the same number of Electrons as Protons, the number of Electrons can vary slightly (but usually not more than 2 or 3 more or less electrons than the number of Protons). When the number of Electrons does not match the number of Protons, that atom is usually referred to as an Ion.
The number of Neutrons can vary quite a bit from the number of Protons, and when it does, the number of Neutrons is usually more than the number of Protons. An example is Molybdenum (the 2 letter abbreviation for Molybdenum is Mo). It has 42 Protons. As the Atomic Number is equal to the number of Protons, the Atomic Number for Molybdenum is 42. Example: the number of Neutrons in the most common, stable form of Molybdenum is 54 Neutrons.
The Atomic Weight of an atom is very close to the number of Protons plus the number of Neutrons. Electrons have very little mass compared to Protons or Neutrons. Example: the Atomic Number for Molybdenum is 96 (42+54).
One last thing: the size of the atomic nucleus is extremely small compared to the size of the electron cloud, which is effectively the overall size of the "Atom". If the nucleus were the size of a golf ball, the electron cloud would be about 3 miles in diameter. The nucleus is so small compared to the electron cloud (and using the example of the golf ball sized nucleus), from the closest point the electron would get to the nucleus, you could not see the nucleus (that little golf ball) with the best human vision. Crazy!
Hope this helps understand basic atomic structure.