Grade 9 CIE Checkpoint Science 1113

Here’s what a scientist might say. Did you find any evidence to support or justify these ideas? Are there any questions that you still need to answer?
Everything is made from atoms. They make up the elements, such as oxygen, mercury and iron. There are three basic parts to an atom – electrons, protons and neutrons. All the atoms of an element are the same. However, the atoms of each element are different from the atoms of other elements because they have different numbers of electrons, protons and neutrons. The atoms in some elements can be arranged in different ways and form different materials. For example, carbon can be charcoal, graphite, diamond or graphene depending on the arrangement of its atoms. Atoms of different elements can combine to make molecules, such as hydrogen and oxygen which combine to make water molecules. Different combinations of atoms make different materials. Materials exist in different states, as solid, liquid or gas. The atoms in the solid, liquid and gas forms of any material are the same, but they are arranged differently. Draw an annotated diagram to show how you think nuclear reactors change one element into another.