Atoms

An atom is the smallest unit of matter that retains the properties of an element. It consists of a nucleus, which contains protons and neutrons, and a cloud of electrons that orbit the nucleus. Atoms are the building blocks of all matter and are composed of various combinations of protons, neutrons, and electrons.

Structure of an Atom

The nucleus of an atom is made up of positively charged protons and neutrally charged neutrons. The electrons, which are negatively charged, orbit the nucleus in energy levels or shells.

Protons

Protons have a positive charge and are located in the nucleus of an atom. The number of protons in an atom determines the element it is.

Neutrons

Neutrons have no charge and are also found in the nucleus of an atom. They help stabilize the nucleus and are crucial for the stability of the atom.

Electrons

Electrons have a negative charge and orbit the nucleus in specific energy levels. The number of electrons in an atom is equal to the number of protons, giving the atom a neutral charge overall.

Atomic Number and Mass Number

The atomic number of an element is the number of protons in its nucleus. The mass number is the total number of protons and neutrons in the nucleus. This helps in identifying and differentiating between different elements.

Study Guide

1. What is an atom?
2. Describe the structure of an atom.
3. What are the charges of protons, neutrons, and electrons?
4. Explain the concept of atomic number and mass number.

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