300 likes | 303 Views
Learn about the basic concepts of matter, including mass, volume, atoms, molecules, and the different states of matter. Understand the properties of pure substances and mixtures, as well as the characteristics of solids, liquids, and gases.
E N D
Chapter 1 “Introduction to Matter” A. Johnson/J. Reblin Physical Science-8
1.1 Matter has mass and volume. All objects are made of matter. Matter is anything that has mass and takes up space. Air, water, and living things are all made of matter. All matter is made up of small particles called atoms. Light and sound are not matter. Neither takes up space or is made of particles. Mass, weight, and volume are physical properties or characteristics of matter.
Mass • Mass is a measure of the amount of matter in an object. • Mass can be measured with a triple beam balance. • Large masses are measured in kilograms (kg); Small masses are measured in grams (g). • The mass of an object increases as more matter is added.
Weight • Weight is the downward pull of an object due to gravity. • Weight may be measured with a spring scale. • The SI unit of weight is the newton (N); The US Customary unit for weight is pound (lb). • 1 kilogram equals 9.8 N • 1 kilogram equals 2.2 lbs
Concept Check • Are weight and mass the same? Explain. • What would someone’s weight be on the moon if they weighed 100 pounds on Earth? Give your answer to newtons.
Volume • Volume is a measure of the amount of space an object takes up. • Volume of regular objects can be determined using a formula: V= length X width X height • Volume of regular objects is expressed in length cubed or length to the third power (cm3 or m3) • Volume of irregular objects can be determined by the displacement method. • The displacement method requires use of a graduated cylinder. • The SI unit of volume on a graduated cylinder is milliliter (mL)
Volume and Displacement 1. Add water to a graduated cylinder. Measure the amount of the water in the graduated cylinder. 2. Then add the object to the cylinder. Measure the new amount of the water in the graduated cylinder. 3. Finally, use the difference in amounts to calculate the volume of the object. 3. 270 mL • 200 70 mL (volume of the rock) 1. 200 mL 2. 270 mL
Concept Check • A bar of gold is 10 cm long, 5 cm wide, and 7 cm high. What is its volume?
1.2 Matter is made of atoms. • An atom is the smallest basic unit of matter. • Atoms are building blocks from which all matter is made. • Scientists have identified over 100 different atoms. • Atoms are so small that they cannot be seen by any optical microscope.
Molecule • When two or more atoms join together, they make a molecule. • Can be made of many different atoms, or atoms that are all the same. Examples: H2O, O2 , and O3 • A molecule is the smallest amount of a substance that is still considered to be that substance.
Atoms and Molecules • Atoms and molecules are always in motion. Examples: • Behavior of Solids- • Behavior of Liquids- Food coloring spreads quickly through water. • Behavior of Gases- The darting motion of the dust you observe in the air.
Concept Check • Do atoms have mass? Explain.
1.3 Matter combines to form different substances. • Matter can be classified as pure substances or mixtures. • A pure substance contains a single type of atom or a single combination of atoms that are bonded together. • A mixture contains more than one kind of element, compound, or both.
Pure Substances • Pure substances can be elements or compounds.
Pure Substances • Element • An element is made up of a single kind of atom. • There are over 100 elements. • EX: copper
Pure Substances • Compound • matter composed of 2 or more elements in a fixed ratio • properties of compound differ from those of individual elements • EX: salt (NaCl)
Mixtures • Mixture are classified as homogeneous or heterogeneous. • Substances keep their original identity or properties when mixed. • Substances are not combined in a fixed ratio.
Homogeneous Mixture • Particles or components are evenly mixed or spread evenly throughout • Very small particles • Particles never settle • Example: saline solution
C. Mixtures • Heterogeneous Mixture • Particles or components are unevenly mixed or spread apart • Fairly large particles • Particles settle out or remain suspended within another substance • Example: fruit salad/conglomerate rock
MIXTURE PURE SUBSTANCE Can it be decomposed or broken down by chemical means? yes no yes no Is the composition the same throughout? Matter Flowchart MATTER yes no Can it be separated by physical means? Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element
Solid Liquid Gas Plasma 1.4 Matter exists in different physical states. States of matter are also known as phases.
Solid SOLID: • Particles are close together and usually form a regular pattern. • Particles can vibrate but are fixed in one place. • Most solids are RIGID.
Two Kinds of Solids Amorphous Solids • Atoms are not arranged in a regular repeating pattern • Solid is flexible. Crystalline Solids • Atoms are arranged in a regular repeating pattern called a crystal lattice. • Solid is rigid.
Liquid • Particles are attracted to one another and are close together. • They are not fixed in place and can move from one place to another (slide over each other). Water Molecules
Gas • Particles are not close to one another and can move easily in any direction • More space between these particles compared to a solid or liquid. • Space between particles increases or decreases with changes in temperature and pressure.
The Fourth State - PLASMA • High temperature, ionized gases • Exists at very high temperatures on the sun or during re-entry from space. • Most abundant form of matter in the universe. • Examples: Neon signs, fluorescent lights, the Northern Lights, and lightening.
Gas Behavior • What happens when the temperature of a gas remains the same and the pressure of a gas is INCREASED? Volume decreases! Boyle’s Law
Gas Behavior • What happens when volume of a gas remains the same and temperature increases? Pressure increases! Gay-Lussac’s Law
Gas Behavior • What happens when pressure of a gas remains the same and the temperature is increased? Volume increases! Jacques Charles Charles’ Law