Bellringer Write your name on the top of the Matter Lab and wait for instructions Tests will be graded by tomorrow Make up test will be Monday during SMART lunch A Happy Birthday Marc and Emeline!!!

Chemistry Basics

Matter Matter – anything that has mass and volume Two subcategories: Pure substances (elements and compounds) Mixtures (homogeneous and heterogeneous)

Pure Substances Matter that only has 1 set of chemical and physical properties Can’t be separated by physical means Ex. Pure water always has the exact same chemical and physical properties under the same conditions Can be divided into two categories: elements and compounds

Elements and Atoms All matter is made of elements Element – substance that cannot be broken down to simpler substances by physical or chemical means 92 naturally-occurring elements and several more synthetic elements (produced in labs)

Elements and Atoms Hydrogen and Helium make up about 99.8% of the elements in the universe (mostly stars) On Earth, Oxygen and Silicon are most common, making up about 75% (mostly rocks and minerals)

Elements and Atoms Other common elements on Earth: Aluminum, Iron, Calcium, Sodium, Potassium, and Magnesium

Elements and Atoms Atom – smallest part of an element that still has all of the characteristics of that element Atoms break down into smaller, subatomic particles (protons, neutrons, electrons)

Matter Compounds – substances made of two or more combined elements Example: carbon dioxide, CO2, is made of the elements carbon and oxygen

Mixtures Mixtures – combinations of two or more components that retain their identities Can be separated by physical means Example: a salad is a mixture of lots of ingredients, but the tomato will still be red and taste like a tomato

2 Types of Mixtures Heterogeneous – individual parts are easily recognizable Homogeneous – look the same throughout Example: a solution of salt water

Acids and Bases Acids – produce hydrogen ions (H+) in solution pH <7 Carbonic acid – acid produced from carbon dioxide dissolving in water, plays a major role in chemical weathering of rocks

Acids and Bases Bases – produce hydroxide ions (OH-) in solution pH >7 Neutral – pH =7 Ex: distilled water (other types of water may be slightly acidic or basic based on impurities and minerals found in the water)

Physical and Chemical Changes Chemical property – a substance’s characteristic that indicates whether it can go through a chemical change Examples: flammability, oxidation (reaction with oxygen) Physical property – a substance’s characteristic that can be observed without changing the substance’s identity Examples: color, shape, size, phase of matter

Physical and Chemical Changes Physical change – changing a physical property of matter without changing the type of matter Example: phase change (ice, water, and steam are all still chemically H2O)

Physical and Chemical Changes Chemical change (chemical reaction) – a change from one substance to another substance Represented with chemical equations

Physical and Chemical Changes Law of Conservation of Matter – matter may chemically or physically change, but the quantity stays the same (matter is NOT created or destroyed)

Phase Changes Four phases of matter in the universe – solid, liquid, gas, and plasma A substance changes to different phases of matter with the addition or removal of heat

Phases of Matter Plasma -- gases heated to temperatures greater than 5000oC So hot they glow Found in stars, lightning, and neon signs

Phase Changes

Phase Changes Evaporation

Post Lab Refer back to your lab sheet Define the vocab on the front Flip over to the back and complete the post lab for each item DO NOT CHANGE YOUR ORIGINAL ANSWERS Put in basket when you are done Sign up for Google Classroom Find something to work on quietly

Why teach chemistry in an Earth Science class Why teach chemistry in an Earth Science class? Because the whole Earth is made of atoms and elements! First, a little background: http://ed.ted.com/lessons/where-does-gold-come-from-david-lunney Get out a sheet of paper. While watching the second video (America’s Gold), write down: 3 things you already knew 2 things you learned in the video 1 thing you’d like to learn more about You are an HONORS class. I expect honors-level responses (not “I already knew we lived in America”). Be thoughtful and specific!