Introduction to Chemistry (includes bonding, water, and ph) C1

Introduction to Chemistry (includes bonding, water, and ph) C1

Do Now: What are atoms made up of and list the location of each particle. Finish up Labs Chemistry review Homework: Read, take notes on 2.1 to 2.4

Do Now: Pull out your homework (2.3) List 5 reasons why you know this tree is alive. Be specific!

Objectives The student will be able to Identify the particles that make up an atom

What is the science of chemistry? Study of the composition and properties of matter How does chemistry relate to biology? All organisms are composed of chemical substances Properties and reactions of chemical substances are essential to all living things

Atoms and Elements Review

Structure of an Atom Protons are neutrons are found in the nucleus Electrons are found in valence shells surrounding the nucleus. The 1st shell holds 2 electrons The rest hold 8 All atoms want 8 electrons in their outer shell. This determine the number of bonds it can make

Chemical Bonds Atoms can join with other atoms to form stable substances. A force that joins atoms is called a chemical bond. A compound is a substance made of the joined atoms of two or more different elements.

Chemical Bonds An atom is chemically stable when its outermost energy level (shell) is filled Most atoms are not stable, so they tend to react (or combine with other atoms) in ways that make them more stable.

Chemical Bonds A covalent bond forms when two atoms share one or more pairs of electrons to form a molecule. Covalent bonds are the strongest bonds A molecule is a group of atoms held together by covalent bonds. Water:

Draw a Covalent Bond! Let s draw a CH₄

Chemical Bonds-Ionic Bonds Sometimes atoms or molecules gain or lose electrons. An atom or molecule that has gained or lost one or more electrons is called an ion. Ions of opposite charge may interact to form an ionic bond. Ionic bonds in sodium chloride, NaCl (table salt), are formed by the interaction between sodium ions, Na+, and chloride ions, Cl. Ionic bonds are relatively weak bonds

Let s Draw an Ionic Bond! NaCl

Chemical Bonding Why is carbon the best atom for bonding? - It has 4 valence electrons so it can form 4 covalent bonds. Dogs Teaching Chemistry! https://www.youtube.com/watch?v=_m9khs87xq8

Do Now Answer the follow question: Describe what happens when an ion forms

Do Now Get a new Do-Now Answer Sheet Date: 10/4/16 What is the difference between ionic and covalent bonds?

Water In a water molecule, the shared electrons are attracted more strongly by the oxygen nucleus than by the hydrogen nuclei. Molecules with an unequal distribution of electrical charge, such as water molecules, are called polar molecules This attraction between two water molecules is an example of a hydrogen bond a weak chemical attraction between polar molecules.

Water: Polarity Covalent bond between two hydrogen atoms and one oxygen atom O pulls H electrons closer to O Leads to slight negative charge on O and slight positive charge on H

Chemical Bonds

Water: Hydrogen Bonding Forms between H of one water atom and O of another Holds 2 water molecules together Weak bond Easily broken To break, bonds have to gain or lose energy Causes change in state (solid, liquid, gas)

Water: Cohesion Cohesion - attractive force between particles of same kind Reason for surface tension molecules stick together

Water: Adhesion & Capillarity Adhesion - attractive forces between unlike substances Water sticking to The inside of a glass Ex: Paper towel and water Capillary Action

Do Now Take out your water lab What is a vaccine? Have you ever had the flu shot?

a vaccine is a substance used to stimulate the production of antibodies and provide immunity against one or several diseases It does not cause the flu!

Agenda Review water lab ph notes ph worksheet Ph and water quiz Homework: Complete the Carbohydrates EDpuzzle. Write down the questions on a separate sheet of paper. You may have to download the Edpuzzle App. If you don t want to, you can use the school computers to watch the video. Please plan accordingly

What is the ph scale?

ph Scale A change of 1 ph unit represents a tenfold change in the acidity of the solution. For example, if one solution has a ph of 1 and a second solution has a ph of 2, the first solution is not twice as acidic as the second it is ten times more acidic.

Complete the ph scale worksheet