A Closer Look at Molecules | Science

April 23, 2015 thetasctest

A Closer Look at Molecules

You’re probably already familiar with the science subtest’s high emphasis topic, “From Molecules to Organisms: Structures and Processes,” because of the overview featured in a previous blog post. There, you can learn that organisms have functions and processes in common, including small-scale processes such as those at the molecular level. An example of such a process is how “molecules interact within a network of proteins to serve the needs of the cell, tissue, organ, organ-system, and ultimately the organism.”

To better understand this, and prepare for the TASC Test Assessing Secondary Completion™ Science subtest, you must take a closer look at molecules.

What’s a molecule? 

According to college instructor Sarah Friedl of Study.com, molecules are “a group of two or more atoms chemically bonded together.” Atoms must be paired up with at least one other atom to be considered a molecule.

Friedl explains in-depth: “While many things in nature do come in their pure elemental form, there are of course many other things that do not. Instead, they are combinations of elements. When elements combine, they form molecules.” In their section “The Essentials of Biology Basics,” the experts at For Dummies note that molecules only form when atoms of the same element combine. When molecules of two or more different atoms combine, this is called a compound. In other words, molecules are made of a combination of the same element and compounds are made of a combination of different elements.

Just like the structures and processes molecules participate in, molecules themselves can be simple or complex. A simple molecule is a molecule that is formed by the same elements. Compounds are more complex. For example, glucose (which is a sugar) is composed of many carbon, hydrogen, and oxygen atoms bonded together.

How do molecules and compounds stick together? 

Because molecules and compounds are combinations of elements, there must be something that holds them together. This force that holds molecules and compounds together is called a bond. Instructors at Springfield Technical Community College write, “There are two main ways that atoms can bond to each other to make larger molecules: covalent bonds and ionic bonds.”

Covalent bonds are formed when atoms share electrons in a covalent reaction. The experts at For Dummies define the word covalence as “the number of electron pairs that an atom shares with another atom. The more electron pairs that atoms share, the more stable they are.” In fact, a covalent bond is the strongest type of bond.

Ionic bonds “hold atoms joined together in an ionic reaction. Ionic reactions occur when ions combine and the atoms involved lose or gain electrons.” Ionic bonds are weaker than covalent bonds, however. This is partially because ionic bonds fall apart in water.

Keep reviewing our subject tips on the blog so you can master each TASC test subject.

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