What are they and what do they do? 6/3/2018 Atoms What are they and what do they do?

What are atoms? Atoms are the smallest particles of matter Atoms make up everything around us Molecules are combinations of atoms Elements are only one type of atom Compounds are made up of different types of atoms Hydrogen Gas Water Dan Kelly - Magic of Electrons - PLTW - Atoms

Atoms vs. Elements What is the difference between atoms and elements? Atoms make up elements. To be an element, it can ONLY have ONE type of atom. The terms are often used interchangeably. For example, the Periodic Table of the Elements could also be written as the … Periodic Table of Different Types of Atoms. Dan Kelly - Magic of Electrons - PLTW - Atoms

Let’s Recap What is an atom? What is an element? What is a molecule? Atoms are the smallest particles of matter. What is an element? Elements are made up of only one type of atom. What is a molecule? Molecules are combinations of atoms. What is a compound? Compounds are made up of different types of atoms. What are some examples of these? Dan Kelly - Magic of Electrons - PLTW - Atoms

Components of an Atom Nucleus. Protons: (+) Neutrons: 6/3/2018 Components of an Atom What makes up an atom? At the center of all atoms is the Nucleus. The nucleus contains protons and neutrons. Protons: (+) Positively charged atomic particles Neutrons: Uncharged (neutral) atomic particles Demonstration on positive vs. negative Dan Kelly - Magic of Electrons - PLTW - Atoms

Components of an Atom Electrons: (-) What makes up an atom? 6/3/2018 Components of an Atom What makes up an atom? Orbiting around the nucleus are the electrons. Electrons: (-) Negatively charged atomic particles Nature prefers balance so if a particle is positively charged, it will attract negatively charged particles and vice-versa. Demonstration on positive vs. negative Explain orbiting free-fall Dan Kelly - Magic of Electrons - PLTW - Atoms

Components of an Atom Electrons: Protons: Neutrons: Recap 6/3/2018 Components of an Atom Recap Where would you find the following parts of an atom and what is its charge? Protons: In the center of the atom Positive charge Neutrons: Uncharged Electrons: Orbiting the atom Negative charge Demonstration on positive vs. negative Explain orbiting free-fall Dan Kelly - Magic of Electrons - PLTW - Atoms

Atomic Number How many protons are in this nucleus? 6/3/2018 Atomic Number The atomic number is equal to the number of protons in the nucleus of an atom. The atomic number identifies the element. How many protons are in this nucleus? (assume the protons are red) Demonstration on positive vs. negative Dan Kelly - Magic of Electrons - PLTW - Atoms

Matter Notes Five states of Matter Phases of matter, mixtures and solutions. Five states of Matter Bose-Einstein condensate solids liquids gases plasma

Changing states of matter Elements and compounds can move from one phase to another phase when special physical forces are present.

Phase changes All matter can move from one state to another. Energy makes the difference. Freezing point is when a liquid turns into a solid. Melting point is when a solid turns into a liquid. Pressure can also make a difference.

Physical vs. Chemical Change Physical changes are about energy and states of matter. Chemical changes happen on a molecular level. You can cause physical changes with forces like motion, temperature, and pressure.

Physical vs. Chemical Change Chemical changes happen on a much smaller scale. Melting a sugar cube is a physical change because the substance is still sugar. Burning a sugar cube is a chemical change. The energy of the fire has broken down the chemical bonds. The actual molecules have changed their structure http://ed.ted.com/lessons/the-chemistry-of-cookies-stephanie-warren

Solids Solid holds its shape. The atoms still spin and the electrons fly around, but the entire atom will not change position. More than one type of compound in a solid it is called a mixture. Atoms arranged in a regular repeating pattern called a crystal lattice.

Liquids Fill the shape of their container. Tops are flat because of gravity. Difficult to compress. Liquids have cohesive (sticky) forces at work that hold the molecules together. http://www.wimp.com/neatscience/

Evaporation Evaporation is all about the energy in individual molecules, not about the average energy of a system. The average energy can be low and the evaporation still continues

Evaporation The energy you can measure with a thermometer is really an average of all the molecules in the system. There are always a few molecules with a lot of energy and some with barely any energy at all. Examples: Cold hands when wet, Wet hair give you a cold.

Gas Gases can fill a container of any size or shape. Gases are random groups of atoms. Vapor and gas mean the same thing. Can be compressed fairly easily. http://www.dump.com/2012/01/28/liquid-nitrogen-into-the-swimming-pool-video/

Plasma Made up of free electrons and ions of the element. Balanced charge. Northern Lights or ball lightning Examples: Neon signs Stars http://www.dump.com/2012/01/28/powerful-solar-storm-sets-off-amazing-northern-lights-show-video/

Bose-Einstein Condensate Two scientists, Satyendra Bose and Albert Einstein, predicted it in the 1920. In 1995, two scientists, Cornell and Weiman, finally created this new state of matter. They are super-unexcited and super-cold atoms.

Bose-Einstein Condensate When you get to a temperature near absolute zero something special happens. Atoms begin to clump. A group of atoms takes up the same place, creating a "super atom."

Mixtures vs Solutions vs Compounds

Mixtures Combination of two or more substances that are not chemically combined No new substance formed Do not exist in fixed proportions to each other They just mix Most natural substances are mixtures Can be physically separated into pure compounds or elements Can be separated by mechanical means Physical properties can change Any combination of solid, liquid or gas can be a simple mixture

Solutions Homogeneous is molecules that are mixed up in a completely even distribution Heterogeneous is not (Macaroni Salad)

Solutions A solute is the substance to be dissolved (sugar). The solvent is the one doing the dissolving (water). Can be solids in liquids, gases in liquids, or even two in same state. http://www.youtube.com/watch?v=ASLUY2U1M-8

How to make a Solution Solute=Sugar, Solvent=Water, System=Glass. 1. The solute is placed in the solvent and the concentrated solute slowly breaks into pieces.

How to make a Solution 2. The molecules of the solvent begin to move out of the way and they make room for the molecules of the solute. Example: The water has to make room for the sugar molecules.

How to make a Solution 3. The solute and solvent interact with each other until the concentration of the two substances is equal throughout the system. The concentration of sugar in the water would be the same from a sample at the top, bottom, or middle of the glass.

Solubility Solubility is the ability of the solvent (water) to dissolve the solute (sugar). Increase Temp: allows more solids and less gas. Increase Pressure: more gas (think coke) Molecular Structures: In water, sugar vs. oil. Oil has low solubility in water. http://www.dump.com/2012/02/19/never-wet-nanotechnology-to-the-rescue-video/ http://www.youtube.com/watch?v=h5yIJXdItgo

Mixtures Mixture = substances held together by physical forces, not chemical Distilled water, it's a pure substance. Salt water has something else in it that can be removed by physical forces. (boiling off the water)

Mixtures Solutions are also mixtures. A solution can also be made of two liquids. Even something as simple as bleach and water is a solution.

Other types of Mixtures Alloys are basically a mixture of two or more metals. Metallurgists (people who work with metals) sometimes add chromium (Cr) and/or nickel (Ni) to steel. (Stainless Steel)

Other types of Mixtures Amalgams are alloys that combine mercury and other metals. Mercury as "quicksilver" or the metal that is liquid at room temperature.

Other types of Mixtures Emulsions are Colloids that have a mixture of oils and waters As time passes, the oil and water will separate to their original states. (Think salad dressing)