Calcium Ions: Definition & Formula

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  • 0:04 Definition of a Calcium Ion
  • 1:09 Importance to Life
  • 1:59 The World without Calcium Ions
  • 3:15 Lesson Summary
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Lesson Transcript
Instructor: Brekke Peterson Munks
Have you ever heard of a calcium ion? Did you know that is it super important to your everyday life? Luckily you have come to the right spot! In this lesson, you'll learn what a calcium ion is, why it is important and how to identify it.

Definition of a Calcium Ion

Have you ever looked at a glass of milk and thought, I wonder what makes up that milk? Have you ever looked at a bone and wondered why it was hard and white? The answer to both of these questions lies in their chemical make-up, which contains a chemical element called calcium. Calcium is a chemical element found in nature. It is a metal with a chemical symbol of Ca.

Calcium is the fifth most abundant element in seawater and is very reactive by itself in nature. Calcium also has a positive charge of 2. This makes it an ion. An ion is an atom of a chemical element that has an unequal number of electrons compared to protons. Remember that electrons are negative charges, and protons are positive charges. In the case of the calcium ion, we have a calcium element with a positive charge of 2. Positively charged atoms are called cations. This simply means that the element calcium needs two more electrons to equal the number of protons that it has; this balances the charge, or makes it zero.

The Importance of Calcium Ions to Life

Calcium is incredibly important to life, especially for humans, but also for all other living creatures. That's because this element is important in cell function. Calcium is similar to the telephone wires that we use to communicate across the country - it's the element used to signal cells that fluid needs to be pumped in or out, or another nutrient is needed to function properly.

Calcium is also the element that is the major constituent in the formation of bones, teeth and shells. To form these important body structures, calcium binds with a compound called phosphate. This produces a compound called hydroxylapatite. This creates the white color of bones, teeth and shells. It is also this calcium phosphate structure that creates a protein called casein in milk, which is white.

The World Without Calcium Ions

A world without calcium would be very brittle and lack life. As noted earlier, calcium ions are important for cellular messaging. What does this mean? Our central nervous system uses chemicals to send messages to the brain to function. Calcium is one of those messengers, also known as a neurotransmitter. It helps to tell muscles to move when we walk, run or even pump blood from our heart.

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