Final answer:
The correct answer is 2) element. An atom consists of protons, neutrons, and electrons, which are subatomic particles, not elements. Elements are defined by their number of protons and are composed of atoms.
Step-by-step explanation:
Atoms and Their Components
An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are very small; typical sizes are around 100 picometers (a ten-billionth of a meter, in the short scale).
Atoms are composed of three types of subatomic particles. The positively charged protons and neutrally charged neutrons reside in the nucleus, the core part of the atom, while the negatively charged electrons orbit the nucleus. The number of protons determines the atomic number and thus identifies the element.
When answering the question of which of the following is not present in an atom: 1) electron, 2) element, 3) neutron, 4) proton, the correct answer is 2) element. An element is a substance consisting of atoms which all have the same number of protons. Atoms themselves are not elements, but are the constituent particles that form elements.
The properties of protons, neutrons, and electrons define the behavior and characteristics of atoms. Protons and neutrons give an atom its mass, while electrons determine an atom's charge and reactivity.
Atoms maintain charge neutrality because their number of electrons is equal to their number of protons, which cancels out the positive and negative charges, resulting in an atom with no net charge. Therefore, the statement that atoms are always neutral in charge because they have the same number of protons as electrons is true.