ATI TEAS 7 Introduction to Chemistry Questions with complete solutions 2023

ATI TEAS 7 Introduction to Chemistry Questions with complete solutions 2023 Matter is anything that takes up space and has mass atom is the basic unit of matter. They are also known as elements number of protons in an atom determines its identity (which element it is). atomic number mass number is determined by adding the number of protons and the number of neutrons. charge of an atom is determined by the numbers of protons and electrons. Isotopes atoms of the same element that have different numbers of neutrons and, therefore, different masses. Electron negative charge Proton positive charge Neutron neutral charge valance electrons number of unpaired electrons in the outermost shell 2 electrons are in the 1st shell 8 electrons are in the 2nd shell 18 electrons are in the 3rd shell full shell Electrons are located in an atom's electron cloud, divided into shells. Atoms are constantly seeking to gain, share, or give up electron in order to have a full shell. column or group have the same number of valence electrons in their outermost shell, there are exceptions Transition metals have 2 valence electrons (columns 3-12) atoms in columns 13-18 have the number of valence electrons equal to the column number minus 10. noble gas have 8 valence electrons and a full outermost shell. Exception: Helium (also noble gas) only has 2 valance electrons, its full. Cohesion is the tendency of particles of the same kind to stick to each other. States of matter energy A solid has the lowest amount of energy because its particles are packed close together. Liquids have more energy than a solid, and gases have more energy than solids or liquids because the cohesive forces are very weak. Matter can change phases if it either absorbs or releases enough energy. Sublimation phase change from solid directly to gas Deposition phase change from gas directly to solid When does a substance experience an increase or decrease in temperature? Only when it is entirely in one state of matter. While a substance changes states its temperature remains constant. Any energy that is absorbed or released is used to change the way in which the particles interact with one another. Properties of matter there are physical and chemical properties Physical properties categories intensive and extensive properties Intensive properties do not depend on the amount of matter present, such as color or density. Extensive properties do depend on the amount of a sample present, such as mass and volume. Water is what type of molecule? is considered a polar molecule, a molecule where one end is slightly negative and the other end is slightly positive. adhesiveness is the attraction of water to other substances. Cohesiveness is the attraction of water to itself, and adhesiveness is the attraction of water to other substances. Diffusion is the tendency of molecules and ions to move toward areas of lower concentrations until a substance is uniform. Osmosis is the diffusion of water and the movement of molecules from an area of high concentration to an area of lower concentration. octet rule any atom that does not have a stable electron configuration of eight valence electrons will lose, gain, or share electrons to become stable. Exceptions are hydrogen and helium since their outer layer is full with 2 electrons. Periodic table row Elements have the number of energy levels equivalent to the row they are in. Ionic bonds are formed when electrons are transferred from a metal atom to a nonmetal atom. anion it has a net negative charge since it gains negatively charged particles, electrons.