1.which two particles are found in an atoms nucleus?

2. which two particles in an aton are equal in number?
3. what two particles account for almost all of the mass of an atom?

To answer these questions, we need to understand the basic structure of an atom.

1. The two particles found in an atom's nucleus are protons and neutrons. The nucleus is the central part of an atom, which contains most of its mass and positive charge. Protons have a positive charge, whereas neutrons have no charge (they are neutral).

2. The number of protons and electrons in an atom is equal. Electrons are negatively charged particles that orbit around the nucleus in specific energy levels or shells. In a neutral atom, the positive charge of the protons in the nucleus is balanced by the negative charge of the electrons.

3. The two particles that account for almost all of the mass of an atom are protons and neutrons. Electrons are much smaller and have negligible mass compared to protons and neutrons. Protons and neutrons contribute to almost the entire mass of an atom, while electrons contribute very little to the overall mass.

In order to find this information, you can refer to reliable scientific sources such as textbooks, educational websites, or consult experts in the field of atomic structure. These sources will provide detailed explanations and diagrams to better understand the composition and characteristics of atoms.