MIDTERM INFO The Midterm is comprehensive –County Assessment (1 st & 2 nd Quarter) 50 MC Questions & 1 BCR –Teacher-Designed Exam (1 st & 2 nd Quarter) 25 MC Questions

MidTerm Exam Schedule Tues, 1/15Full Day –Period 4B Exam during the regular time pd Wed, 1/16Day 2 -Examinations – Periods 1 & 2 Schools close 3 hours early. Thurs, 1/17Day 3 -Examinations – Periods 3 & 4A Schools close 3 hours early. Fri, 1/18Day 4 -Examinations – Periods 5 & 6 Schools close 3 hours early.

Chemistry Midterm Review Day #2

Agenda Practice Problems and Review Sheet Homework Review Sheet # 2 – due Monday or Tuesday

Practice Problem Difference between an organic and inorganic cpd is…

Organic cpds have a C - H bond. Inorganic cpds can have C or H but not this bond.

Review Show accuracy and precision using a dart board.

Accuracy vs. Precision Accuracy – closeness to the actual value Precision – reproducibility

Review What is the Law of Conservation of Mass and Energy?

Mass and energy are neither created nor destroyed during ordinary chemical reactions or physical changes. They are just rearranged! The mass of all the reactants is equal to the mass of all the products. The energy that goes in to the reaction is equal to the energy that comes out. Answer

Review Draw Bohr’s Model for Argon

Review Where on the periodic table do we find the s, p, d, and f blocks?

Practice Problem Write the formulas for the following: (a) barium carbonate, (b) sodium phosphate, and (c) carbon tetrachloride

Answers a) BaCO 3 b) Na 3 PO 4 c) CCl 4

Review Question Name the following compound: Cu(BrO 3 ) 2

Answer Copper(II) bromate

Review List the symbol, charge, and penetration power for each type of radiation: –Alpha particles –Beta particles –Gamma radiation

NameSymbolChargeMass(amu)PenetrationPower Alpha cm air cm tissue no penetration through lead Beta cm air cm tissue cm lead Gamma m air 500 cm tissue 3 cm lead

Alpha Radiation α U ? + He 92 2 Uranium-238 Alpha Particle Note that the mass number always decreases by 4 after the alpha emission. Atomic number decreases by 2

Alpha Radiation α U Th + He Uranium-238 Thorium-234 Alpha Particle

Beta Radiation β Th + e Thorium-234Beta particle By combining the charges from the bottom of the two symbols, figure out the symbol for the remaining particle ?

Beta Radiation β Th Pa + e Thorium-234 Beta particle During the emission, a Thorium neutron becomes a proton and an electron. The electron is emitted as a beta particle. Pa Protactinium- 234

Practice Problem Give 2 examples of quantitative data. Give 2 examples of qualitative data.

Answers Quantitative data = how big, how fast, how tall = measured Qualitative = relates to our 5 senses – color, texture, odor, shape

Practice Problem A small sphere has a mass of 2.5 grams. It has a density of 2.9 g/cm 3. Determine the volume of the sphere.

Answer 0.86 cm 3

Review How can we tell individual element apart using a spectrometer?

Elements Emit only Specific Wavelengths Individual elements emit a spectrum containing discrete lines This is called a line spectrum

Review Label each substance as a chemical change, physical change, chemical property, or physical property: a. density b. melting an ice cube c. reacts with oxygen d. penny turns green e. dissolving sugar f. Color g. Grilling a hamburger

Review Label each substance as a chemical change, physical change, chemical property, or physical property: a. density – physical property b. melting an ice cube – physical change c. reacts with oxygen – chemical property d. penny turns green – chemical change e. dissolving sugar – physical change f. Color – physical property g. Grilling a hamburger – chemical change

Review Classify each of the following as: elements (E), compounds (C),homogeneous mixtures (Hom), or heterogeneous mixtures (Het). 1.Copper3. Lemonade 2.Carbon dioxide 4. Salad Think of two other examples of each.

Answer 1.Copper - E 2.Carbon dioxide - C 3.Lemonade – Hom 4.4. Salad – Het

Review If electrons in an atom have the lowest possible energy, the atom is in a state. If the electron absorbs energy from an outside source (heat, electrical current), the atom is in an state. How does this pertain to a flame test?

Answer If electrons in an atom have the lowest possible energy, the atom is in a ground state. If the electron absorbs energy from an outside source (heat, electrical current), the atom is in an excited state.

Review Identify the shape of each of the following molecules: (a) ammonia (NH 3 ) (b) water (H 2 O)

Answer (a) Pyramidal (b) Bent

Review List radiation of the electromagnetic (EM) spectrum from shortest to longest wavelength.

Answer Gamma, x-rays, UV, visible light, IR, Microwave, radio Visible light = VIBGYOR