<h3>
Answer:</h3>

<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Physics</u>
<u>Energy</u>
Elastic Potential Energy: 
- U is energy (in J)
- k is spring constant (in N/m)
- Δx is displacement from equilibrium (in m)
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
k = 7.50 N/m
Δx = 0.40 m
<u>Step 2: Find Potential Energy</u>
- Substitute in variables [Elastic Potential Energy]:

- Evaluate exponents:

- Multiply:

- Multiply:

The dens or the odontoid process of the axis or the second cervical spine forms a pivot point with the atlas or the first cervical vertebrae that is responsible for the nodding and the rotational movements of the head. This is reinforced by ligaments and the atlanto-occipital joint that allows the head to make a nodding or up and down movement on the vertebral column.
1. b An element is the simplest form of a substance.
3. a Atoms are comprised of particles such as protons, neutrons, and electrons.
2. c Atoms are tiny pieces of matter.
4. d Phase refers to the state of matter: gas, liquid, and solid.