Facts At Your Fingertips: Energy and forces – Electricity All atoms contain positively charged protons and negatively charged electrons. Electricity is a flow of charged electrons from one place to another. When electrons are transferred between substances, it can cause a buildup of negative charge in one place and positive charge in another— sometimes with … Read more
Facts At Your Fingertips: Energy and forces – Atom power An enormous amount of energy is locked up inside the nucleus of an atom. This can be released by splitting the nucleus apart in a process known as fission. This energy can also be unleashed by fusion, which involves squeezing nuclei together. Nuclear fission To … Read more
Facts At Your Fingertips: Energy and forces – What is energy? Energy is what makes everything happen. It cannot be created or destroyed, but it can be transferred. For example, kicking a ball transfers energy from the person to the ball. Energy can also be converted from one form to another—as when the chemical energy … Read more
Facts At Your Fingertips: Energy and forces Everything in the universe is constantly affected by energy and forces. A roller coaster is a good example of energy and forces in action. Fuel provides the energy needed to generate the force that pulls the roller coaster to the top of the slope. The stored potential energy … Read more
Facts At Your Fingertips: Matter and materials – Using materials Throughout history, people have used and reused materials. Many natural substances can be adapted or changed to produce new substances. For example, soft clay can be turned into hard pottery, sand can be transformed into glass, and iron and carbon can be combined to form … Read more
Facts At Your Fingertips: Matter and materials – Acids and bases Acids and bases are chemical opposites: acids produce positively charged hydrogen ions and bases produce negatively charged hydroxide ions. Many acids and bases can be combined to produce useful substances, such as salts and soaps. Acids Some powerful acids are very corrosive, which means … Read more
Facts At Your Fingertips: Matter and materials – Reactions and changes Physical changes occur when substances change state. Chemical reactions occur when the atoms in molecules are rearranged to create different molecules. Changes caused by physical reactions are usually easy to reverse, while chemical changes are not. Chemical reactions These reactions can be caused by … Read more
Facts At Your Fingertips: Matter and materials – Mixtures and compounds Different elements can be combined to create new substances. When atoms and molecules chemically combine to form a substance, it is called a compound. If no chemical reaction takes place—as when mud is added to water—a mixture is formed. Compounds These are often very … Read more
Facts At Your Fingertips: Matter and materials – Elements A chemical that is made up of atoms of just one type is known as an element. Although all atoms are made of the same basic parts—protons, neutrons, and electrons—not all atoms are the same. It is the number of these parts that gives the atom—and … Read more
Facts At Your Fingertips: Matter and materials – Molecules Most atoms do not exist on their own, but bond with other atoms—either ones of their own type or of another element—to form molecules. Atoms join together by sharing their electrons, a process known as chemical bonding. Simple molecules The natural state of oxygen is nearly … Read more
