Educational diagram illustrating the parts of an atom, including protons, neutrons, and electrons, with definitions and examples.

Problem Description:

The image is an educational worksheet about the parts of an atom. The task involves filling in blanks related to the structure and properties of atoms, specifically focusing on protons. The provided text describes protons as positively charged particles located in the nucleus, with a mass of one atomic mass unit (amu). It also mentions that the number of protons determines the element of an atom, giving examples for hydrogen (1 proton) and helium (2 protons).

Solution and Explanation:

#### Step 1: Understand the Structure of an Atom
An atom consists of three main subatomic particles:
1. Protons: Positively charged particles located in the nucleus.
2. Neutrons: Neutral particles (no charge) located in the nucleus.
3. Electrons: Negatively charged particles that orbit the nucleus in energy levels or shells.

The nucleus is the central part of the atom, containing protons and neutrons, while electrons are found outside the nucleus in specific orbits.

#### Step 2: Analyze the Given Information
The worksheet provides the following key points about protons:
- Protons are positively charged particles.
- They are located in the nucleus of the atom.
- Each proton has a mass of one atomic mass unit (amu).
- The number of protons in an atom determines its element.
- Examples are given:
- Hydrogen has 1 proton.
- Helium has 2 protons.

#### Step 3: Fill in the Blanks
Based on the information provided, the blanks can be filled as follows:

1. Positively charged particles in the nucleus: This refers to protons, which have a positive charge and are located in the nucleus.
2. Mass of one AMU: Each proton has a mass of one atomic mass unit.
3. Determines the element: The number of protons in an atom determines what element it is. For example:
- Hydrogen has 1 proton.
- Helium has 2 protons.

#### Step 4: Verify the Answers
- Protons are indeed positively charged and located in the nucleus.
- The mass of a proton is approximately one atomic mass unit.
- The number of protons defines the atomic number, which identifies the element. Hydrogen (H) has 1 proton, and helium (He) has 2 protons.

Final Answer:

The completed sentences are:
1. "Positively charged particles in the nucleus."
2. "One AMU."
3. "Element."
4. "One."
5. "Two."

Thus, the final answer is:
\boxed{Positively, One, Element, One, Two}