Catalyst Pot A Pot B Xavier conducted the

Catalyst Pot A Pot B Xavier conducted the scientific experiment depicted above. 1. What is the independent variable in Xavier’s investigation? 2. Which pot would be his control group? Why? 3. What are some control variables in his experiment? 4. What do the flower, pot, spoon, fertilizer, and air have in common?

Subway Winners… Cristina & Darion

Today’s Objectives SWBAT define ‘element’ SWBAT define ‘chemical symbol’ SWBAT identify the chemical symbol of common elements SWBAT draw Bohr models for elements 1 -20

WHAT IS INSIDE AN ATOM? All atoms are made of the same 3 subatomic (smaller than an atom) particles. • Protons • Electrons • Neutrons

The Atom Organization The nucleus is in the center A cloud of electrons surround the nucleus The electron cloud has energy levels where electrons occupy Each energy level can only hold a specific number of electrons

Atoms are made of protons (+), neutrons, and electrons (-). The number of protons in an atom determines which element it forms

How is C different from Ca? The type of element an atom is depends on the number of protons in the nucleus Atomic Number = Number of Protons Atomic number: whole number on the periodic table

PREVIEW of the Periodic Table Atomic Number Chemical Symbol Atomic Mass

Atoms in Elements Atoms of the same element are the same. Atoms of different elements are different.

Atoms All elements have no charge (neutral) in their pure form Number of protons (+) = number of electrons (-)

What is an Element? Scientist used to believe that matter was made up of four elements (air, earth, fire and water) but, we now know that all matter in the universe is made of slightly more than 100 different substances called elements.

What is an Element? Pennies are made from zinc and given a coating of copper. Each time you breath, you inhale oxygen and nitrogen.

Well then, what is an ELEMENT? An element is a pure substance that cannot be broken down into simpler substances by physical or chemical means NOT THIS KIND OF ELEMENT

Well then, what is an element? An element is a pure substance that cannot be broken down into simpler substances by physical or chemical means NOT THIS KIND OF ELEMENT

Well then, what is an element? THESE KINDS OF ELEMENTS

An element is a substance made up of atoms of one type. Examples: Iron (Fe), Lead (Pb), Silver (Ag) Where all the elements listed?

Chemical Symbols Elements are often represented by one or two letter symbols. For example: C is for carbon, O is for oxygen and H is for hydrogen. The chemical symbol is the abbreviation for the name of an element. Chemical symbols consist of: 1 capital letter + 1 lower case

Chemical Symbols Some symbols are derived from Latin. Argentum, Ag for Silver Ferrum, Fe for Iron Hydrargyrum, Hg for Mercury

A complete list of all the elements and their chemical symbols: Periodic Table of Elements

Niels Bohr (1913) Wake up!! This is far from BOHRing! Planetary Model-1913 Nucleus surrounded by orbiting electrons at different energy levels Electrons have specific orbits ELECTRONS ONLY EXIST AT CERTAIN DISTANCES FROM THE NUCLEUS!

Bohr Models of Atoms Bohr Models show electrons floating around the nucleus in specific orbits. The Bohr Model can show 16 p+ 16 no up to 4 energy levels before the model doesn’t work. 1 st can hold up t 0 2 electrons 2 nd-4 th can hold up to 8 electrons Sulfur: 16 protons 16 neutrons 16 electrons

Which Atom am I? O P N

Not BOHR-ING AT ALL!!!

Rules for making a Bohr model: 1. Draw the nucleus with correct number of protons and neutrons 2. Draw each energy level as needed (ie don’t draw all four levels if you don’t need them, as in for hydrogen) 3. Each energy level must be filled before filling the next energy level 4. Each energy level can only hold a certain number of electrons Level 1 = 2 electrons, level 2 and 3 = 8 electrons

Periodic Table Scavenger Hunt You’ll receive a clue for your element. Identify the element. Work with your group to try to solve the scavenger hunt 1 st

Periodic Table Scavenger Hunt

“I Own This” Use your periodic table!