Ch. 1 – Matter, Energy, & Change Chemistry is defined as the following: the study of a chemical substance’s composition, structure, properties, and changes that substance undergoes. How does chemistry affect your life? Fuels, fertilizers, medicines, plastics, water, air, ect. Name some chemical substances Water, sugar, ammonia, air, sand, salt, acids, bases, ect.
Areas of study in chemistry 1. Inorganic chemistry – study of chemistry that deals with all substances that contain elements other than carbon. 2. Organic chemistry – study of chemistry with all substances containing carbon and hydrogen. 3. Biochemistry – study all substances and processes that occur in living things.
4. Physical chemistry – the study of the properties, transformations, and interrelationships of energy and matter. 5. Analytical chemistry – the identification of substances and the qualitative and quantitative determination of the composition of materials.
What is a chemical? Any substance that has a definite composition. Ex. Water, nitrogen, carbon dioxide What is an atom? Smallest unit of an element that maintains the properties of that element. What is an element? A pure substance made of only 1 kind of atom. Ex. N, O, Au, Ag, Pt What is matter? Any thing that has mass and occupies space.
Difference between mass and weight What is mass? How much matter is present What is weight? The measure of the Earth’s gravitational force Mass vs. weight on the moon. Video Clip Do you remember what inertia is? The resistance to change in motion Mass & weight determine an object’s inertia Law of conservation of mass states what? Matter cannot be created nor destroyed; it can only be converted from one form to another.
Types of Energy Explain energy. An objects ability to do work or cause change. 2 types 1. Kinetic energy – which is what? Energy in motion – Examples??? 2. Potential energy – which is what? Stored energy – Examples??? Can someone explain the Law of conservation of Energy?
Properties They allow us to determine one kind of matter from another. 1. Physical properties – describe a substance qualitatively & quantitatively without changing it. Ex. Physical changes cut a board in half & melt ice 2. Chemical properties – a substance that undergoes a change to alter its identity. Ex. Chemical reactions 1 or more substances are converted into a different substance. Reactant Product
3. Extensive properties – depend on the amount of matter that is present. Ex. Mass, volume, amount of energy 4. Intensive properties – don’t depend on the amount of matter that is present. Ex. Melting point, boiling point Evidence of a Chemical Reaction 1. Heat or light is given off 2. Gas is released 3. Precipitate forms Precipitate is a solid that forms in a solution.
4 States of Matter You should already know all four 1. Liquid – has volume, but no shape. 2. Solid – has volume and shape. 3. Gas – no volume or shape. 4. Plasma – a gaseous system composed of positively particles and negatively charged electrons. Plasma is the most abundant matter in the universe. Page 15 Video Clip
What is the release of energy or heat called? Exothermic Ex. Steam from boiling water What is absorption of energy or heat called? Endothermic Ex. Ice What is a mixture? 2 or more substance mixed together Ex. Concrete, air, pop, salt water, granite, ect.
2 Types of Mixtures 1. Heterogeneous mixture – the mixture’s composition & properties are not uniform. You can pick out the different substances. Ex. Concrete, granite, vegetable soup 2. Homogeneous mixture – the mixture’s composition & properties are uniform. Ex. Pop, milk, air, Solutions are homogeneous mixtures. Ex. Solution of HCl or NaOH Pure substances are homogeneous substances with the same pattern in every substance.
Periodic Table This is how elements are arrange. How are they arranged? Atomic Number Groups or families run vertically in columns 18 Groups Periods run horizontally in rows 7 Periods Metals are closer to the left hand side of the staircase. Ductile – drawn into wire Malleable – rolled into sheets Good conductor of electricity and heat
Nonmetals are closer to the right hand side or right of the staircase. Poor conductors of electricity and heat Metalloids are along the staircase Characteristics of metals and nonmetals Semiconductors of heat and electricity Noble gases – group 18; no charge Table 1-2 (page 20)