Question

Give definitions for the terms element and compound. Give five examples of each type of substance.

Short answer

An element is a pure substance made up of only one type of atom and cannot be broken down into simpler substances. Examples include hydrogen (H), oxygen (O), carbon (C), gold (Au), and iron (Fe). A compound is a substance made up of two or more different elements chemically bonded together and can be broken down through chemical reactions. Examples include water (H2O), carbon dioxide (CO2), sodium chloride (NaCl), acetic acid (CH3COOH), and calcium carbonate (CaCO3).

Step-by-step solution

Definition of Element

An element is a pure substance made up of only one type of atom. It cannot be broken down into simpler substances by any ordinary chemical or physical means. Elements are the most basic building blocks of matter.

Examples of Elements

Here are five examples of elements: 1. Hydrogen (H) - the lightest and most abundant element in the universe, found in water and organic compounds 2. Oxygen (O) - a component of the air we breathe, necessary for combustion and respiration 3. Carbon (C) - present in all known life forms, a central component for organic molecules 4. Gold (Au) - a precious metal widely used in jewelry and electronics due to its conductivity and resistance to corrosion 5. Iron (Fe) - a metal with multiple uses, including in construction, tools, and as a component of hemoglobin in red blood cells

Definition of Compound

A compound is a substance made up of two or more different elements that are chemically bonded together. Compounds can be broken down into simpler substances, but only through chemical reactions. The properties of a compound are usually different from those of its constituent elements.

Examples of Compounds

Here are five examples of compounds: 1. Water (H2O) - comprising two hydrogen atoms and one oxygen atom, water is essential for life on Earth 2. Carbon dioxide (CO2) - formed by one carbon atom and two oxygen atoms, it is a greenhouse gas and a byproduct of respiration and combustion 3. Sodium chloride (NaCl) - a compound of sodium and chlorine, it is commonly known as table salt 4. Acetic acid (CH3COOH) - a compound of carbon, hydrogen, and oxygen, it is the primary component of vinegar 5. Calcium carbonate (CaCO3) - a compound of calcium, carbon, and oxygen, it is the main component of shells, limestone, and marble

Key concepts

Chemical Elements

Imagine building blocks so tiny they are the basic units of all matter that we know of. These are the chemical elements, pure substances represented by a single type of atom. What makes each element distinct is the number of protons in its atomic nucleus, dubbed the 'atomic number.' Each element has a unique set of characteristics and can't be simplified or divided into smaller substances through common physical or chemical methods.

Understanding elements is crucial because they form the foundation of chemistry. They can stand alone, or combine in myriad ways to form a universe of different compounds. With 118 confirmed elements, each has its place in the periodic table—a scientific chart that organizes these elements by their atomic structure and properties.

Chemical Compounds

Now, when you mix two or more different elements together and they chemically bond, the result is a chemical compound. This isn't just a jumble of atoms; chemical bonds involve sharing or transferring electrons, holding the different elements firmly together. Importantly, a compound inherits new attributes, often drastically different from its constituent elements. It's like baking a cake—once the ingredients are combined and baked, you can't pick out the flour or eggs; it becomes an entirely new substance.

Compounds can be broken down into simpler substances, but it takes a chemical reaction to do so. This reaction might require heat, light, electricity, or another catalyst. The study of these compounds and how they interact—a field known as chemistry—reveals the complexity and wonder within the substances that make up our world.

Examples of Elements

Examples are often the best way to illustrate what an element is. Let's look at a few:

• Hydrogen (H): Not just abundant, but also the simplest, consisting of one proton and one electron. It's a key player in water molecules and fuel cells.
• Oxygen (O): A life-sustaining element that's all around us as part of the air we breathe and essential for energy production in living organisms.
• Carbon (C): Known as the 'building block of life', it forms a vast array of molecules including the backbone of organic chemistry.
• Gold (Au): Prized for its beauty and electrical conductivity, this metal has been a staple of finance and industry for centuries.
• Iron (Fe): Integral to our civilization's development, it's a core ingredient in steel and vital for transporting oxygen in our blood.

Examples of Compounds

Bringing elements together can yield substances with fascinating properties. Here are some well-known compounds:

• Water (H2O): A simple yet vital molecule, it is necessary for almost all forms of life and covers most of our planet.
• Carbon dioxide (CO2): Despite being a critical greenhouse gas, it's also a product of breathing and pivotal for plant photosynthesis.
• Sodium chloride (NaCl): Better known as salt, this compound has countless uses from seasoning food to melting ice on roads.
• Acetic acid (CH3COOH): This molecule gives vinegar its sour taste and is also used in the production of plastics and solvents.
• Calcium carbonate (CaCO3): Making up seashells and limestone, it is part of the cycle of life and the history of architecture.