On Target? Do this on your Warm Up worksheet! PLEASE put today’s date (2/22/16) in your Monday warm-up square! REVIEW: Why do some substances dissolve in water while others don’t? Explain in complete sentences!

Why do some substances dissolve in water while others don’t? What does salt have to have in order to dissolve in water? CHARGES! What doesn’t dissolve in water? OIL! So what do we know about oil, based on this information? Oil doesn’t have charges!

For today 1.Warmup 2.Review! 3.Big ideas! Objective: I can explain how charges influence the properties of our substances with both words and pictures.

Review From Properties Lab! Groups of chemical compounds share macroscopic similarities – Many hard, crystalline solids with high melting points do not conduct electricity as solids, but do conduct electricity when dissolved in deionized water – Medium-hard, powdery substances with low melting points sometimes dissolve in water partially, but conduct electricity poorly, if they do at all What is causing this on the microscopic level? Electricity is involved (Charges)!

Review from Electroscopes Lab: How do charged objects (plastic knife, glass rod, balloon) react with the tiny paper bits? Did all of them move toward the balloon? What does this tell you about the charge of the paper

Static Electricity Opposites attract! Like charges repel, and opposite charges attract Does it matter which object is positive and which one is negative? – No!

A microscopic view of a stream of water falling past a charged plastic knife and a charged piece of glass.

Solubility Review! “Like dissolves like” Water will dissolve other things with charges! So if you mix 2 things without charges, are they soluble with each other? – YES!

Salt Dissolves in Water How does salt dissolve in water? HINT: What is the formula for salt? What ions does it have? Na + Cl -

Why would salt conduct electricity in water but NOT as a solid? Diamond white boarding! Think about: 1.What might be different about salt as a solid crystal vs in a liquid? 2.What is salt able to do in water? 3.It can move around in water!

How can one substance dissolve in water and NOT conduct electricity (sugar) while another dissolves and DOES conduct electricity (salt)? Think about: 1.How does the conductivity meter work? Does it have charge? 2.How might particles be charged differently? 3.What needs to happen for electricity to be conducted? 4.Why would deionized water not conduct electricity?

How salt dissolves

How sugar dissolves

Big Ideas! In your notebook, fill in the following sentences: 1.Charges are important because__________. 2.Water is attracted to both positive and negative objects because______________. 3.Water can dissolve objects with charges by____________. 4.Salt can conduct electricity in water because_________. Sugar cannot conduct electricity in water because__________.

Big ideas In your notebook: Fill in the following sentences 1.Charges are important because________________. 2.Water is attracted to both positive and negative objects because_________________________. 3.Water can dissolve objects with charges by _________________________. 4.Salt can conduct electricity in water because ____________________. Sugar cannot conduct electricity in water because _________________. Objective: I can explain the 3 different types of bonds by describing how electrons are shared.

Bond Types Blue means to WRITE IN YOUR NOTEBOOK! Objective: I can explain the 3 different types of bonds by describing how electrons are shared.

Now think small…. Sketch this picture in your notebook. See if you can label any of the parts.

EXPLORE: Particular Properties electron proton neutron negative(-) positive(+) neutral Particle (Atom)

Why do atoms need to bond? Valence electrons (outer shell) Atoms are most stable with a full outer shell (8 electrons) Objective: I can explain the 3 different types of bonds by describing how electrons are shared.

3 types of bond Ionic Polar covalent Covalent What is the difference between these bonds? Objective: I can explain the 3 different types of bonds by describing how electrons are shared.

Ionic bonds: Electron transferred What are these? Makes separate charged particles called IONS

Polar Covalent Bonds Sharing electrons but unequally Means partial charge Electrons pulled more toward oxygen than hydrogen Makes one particle with both charges

Covalent bonds Sharing electrons equally Makes one particle with no charge

Categories on data table! What type of bond is table salt? – What other substances share properties with salt? What type of bond is sugar/glucose? – What else shares these properties?

Summary questions What is the charge on unbonded atoms? The charge on unbonded atoms is _______ Why does chlorine have a negative charge when ionically bonded to sodium? Chlorine has a negative charge when ionically bonded to sodium because ______________________ WHY DOES SALT NOT CONDUCT ELECTRICITY AS A SOLID BUT DOES IN SOLUTION?

IONS CAN MOVE!! How is that related to conducting electricity?

Partner Read p What does it mean when something is an electrical conductor? Partner A Partner B Reads paragraph Listens, asks questions Both write down bolded words and agree on their meanings. SWITCH ROLES WITH EACH PARAGRAPH.

ON YOUR OWN Write a summary (with an example) explaining... What does it mean when something is an electrical conductor? – Why would some of our solutions conduct electricity and others not? TURN INTO BASKET

SUMMARY In a conductor, charged particles called ions (+ or – charge) are moving in an electrical current. For example, salt water must have ions moving between the prongs conducting electricity and so completing the circuit, lighting the LED lights. Sugar in water is a insulator because ions do not move so no electricity is conducted.

Notes: If it is blue write it (or draw the diagram if the blue is to sketch). Title: WHY SOLUTIONS CONDUCT ELECTRICITY

Now think small…. Sketch this picture in your notebook. See if you can label any of the parts.

EXPLORE: Particular Properties electron proton neutron negative(-) positive(+) neutral Particle (Atom)

Do you think electricity is conducted the same through a solution? What might be different about the atoms in metals vs. solutions? Ions-atoms with a positive or negative charge Electrolytes-substances that produce ions in water Example) Table salt (NaCl)

Summary questions What is the charge on unbonded atoms? The charge on unbonded atoms is _______ Why does chlorine have a negative charge when ionically bonded to sodium? Chlorine has a negative charge when ionically bonded to sodium because ______________________ WHY DOES SALT NOT CONDUCT ELECTRICITY AS A SOLID BUT DOES IN SOLUTION?

IONS CAN MOVE!! How is that related to conducting electricity?

To think about … How big is the nucleus of an atom compared to the whole atom? Why don’t atoms pass through one another? Why are you hovering cm above your chair right now? WHY IS THIS IMPORTANT?

Attraction and repulsion: One of the probes on conductivity meter is positive while other is negative Opposite charges attract! Ions move in solution toward the opposite charged probe (in salt water, Na+ moves toward –probe; Cl- moves toward +probe) This movement conducts electricity!

Diagrams on pg Copy the picture of the conductivity meter in the solution on page 112. What solution do you think this is? What are the + ions and – ions? 2.Label all the parts of the system. 3.Explain why the light is on in this picture. 4.Which figure on pg. 113 is water and which is baby oil? Use evidence to explain your answer.