1 (A) Elements and Compounds
An element is any substance that cannot be broken down into simpler substances. The smallest unit of an element is called an atom. An element is made up of only one kind of atom. The elements found in living things include carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.
When two or more elements combine chemically, they form a compound. Most elements in living things occur in the form of compounds. Water is a compound. Each water molecule is made up of two hydrogen atoms and one oxygen atom.
Did you know that water makes up about two thirds of your body? Water plays many important roles in cells. For example, most chemical reactions in cells involve substances that are dissolved in water. Also, water molecules themselves take part in many chemical reactions in cells. Most chemical reactions within cells could not take place without water.
Many of the compounds found in living things contain the element carbon, which is usually combined with other elements. Most compounds that contain carbon are called organic compounds. Some important groups of organic compounds found in living things are carbohydrates, lipids, proteins, and nucleic acids. As you may know, many of these compounds are found in the foods you eat. This is not surprising, since the foods you eat come from living things.
When two or more elements combine chemically, they form a compound. Most elements in living things occur in the form of compounds. Water is a compound. Each water molecule is made up of two hydrogen atoms and one oxygen atom.
Did you know that water makes up about two thirds of your body? Water plays many important roles in cells. For example, most chemical reactions in cells involve substances that are dissolved in water. Also, water molecules themselves take part in many chemical reactions in cells. Most chemical reactions within cells could not take place without water.
Many of the compounds found in living things contain the element carbon, which is usually combined with other elements. Most compounds that contain carbon are called organic compounds. Some important groups of organic compounds found in living things are carbohydrates, lipids, proteins, and nucleic acids. As you may know, many of these compounds are found in the foods you eat. This is not surprising, since the foods you eat come from living things.
Elements An element is any substance that cannot be broken down into simpler substances. The smallest unit of an element is called an atom. An element is made up of only one kind of atom. The elements found in living things include carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.
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Compounds
When two or more elements combine chemically, they form a compound. Most elements in living things occur in the form of compounds. Water is a compound. Each water molecule is made up of two hydrogen atoms and one oxygen atom.
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