CHEM R REVIEW PART 1 CHAPTERS 1-8

Chapters 1 & 2: Introduction & Matter and the Changes it undergoes

What are the 5 areas of Chemistry?

What are the steps to the Scientific Method?

What are the 2 types of data?

What is the difference between a Physical and Chemical Change?

Determine whether the following is a physical or chemical change: Sodium hydroxide dissolves in water A pellet of sodium is sliced in two Water is heated and changed to steam (water vapor) Iron rusts Evaporation When placed in water, a sodium pellet catches on fire. Sugar dissolves in water A tire is inflated with air Cookies baking in the over Food is digested in the stomach

Law of Conservation of Mass? What is the Law of Conservation of Mass?

Classification of Matter ALL matter can be classified as a ___________ or ___________

Mixtures can be classified as ___________, ____________ or _____________

What is the difference between an element and a compound?

Determine whether the following is an element, compound, homogeneous mixture, or heterogeneous mixture Copper Salt Silicon Sugar dissolved in water Concrete Sugar (sucrose) Salad Dressing Air Stainless Steel Egg Orange Juice (with pulp) Calcium Chloride Orange Juice (no pulp)

To determine whether a digit in a measured value is significant, you need to apply the following 6 rules: Every nonzero digit in a reported measurement is assumed to be significant 2. Zeros appearing between nonzero digits are significant 3. Leftmost zeros appearing in front of nonzero digits are not significant. They act as placeholders. By writing the measurements in scientific notation, you can eliminate such place-holding zeros 4. Zeros at the end of a number and to the right of a decimal point are always significant. 5. Zeros at the rightmost end of a measurement that lie to the left of an understood decimal point are not significant if they serve as placeholders to show the magnitude of the number 6. There are two situations in which numbers have an unlimited number of significant figures. The first involves counting. A number that is counted is exact. The second situation involves exactly defined quantities such as those found within a system of measurement

ATLANTIC vs. PACIFIC RULE (Determining the number of significant figures)

Addition and Subtraction with Significant Figures The answer should be rounded to the same number of decimal places (not digits) as the measurement with the least number of decimal places Multiplying and Dividing with Significant Figures Round the answer to the same number of significant figures as the measurement with the least number of significant figures

Scientific Notation Chemistry requires you to make accurate and often very small or very large measurements Scientific notation makes them more manageable to work with A single gram of hydrogen contains approximately 602,000,000,000,000,000,000,000 hydrogen atoms

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What is the difference between Accuracy and Precision?

PERCENT ERROR of a measurement is the absolute value of the error divided by the accepted value, multiplied by 100 Percent error = Error Accepted value 100 x

Chapter 4: Atomic Structure

What was Democritus’s contribution to the Chemistry world? J.J Thomson?

What are the 3 types of Subatomic Particles? What are their charges?

What experiment did Rutherford conduct and what were his discoveries?

What does atomic number tell us about an element What does atomic number tell us about an element? What does mass number tell us?

Isotopes What is an Isotope?

How are the atoms of one element different from the atoms of another element? How are isotopes of the same element different?

AVERAGE ATOMIC MASS A weighted average of the atomic masses of naturally occurring isotopes Each isotope of an element has a fixed mass (amu) and a natural % abundance

Calculating Average Atomic Mass Multiply (Atomic mass of isotope) x ( Percent abundance as a DECIMAL) Repeat this for each of the isotopes of the given element Add all of the atomic masses (calculated from step one) to obtain an average atomic mass for that element ***SELF-CHECK…average atomic mass calculated (final answer) should match the atomic mass on the periodic table

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Chapter 5: Electrons in Atoms

The Bohr Model Each possible energy orbit has a fixed energy known as an energy level A quantum of energy is the amount of energy required to move an electron from one energy level to another energy level Energy of an electron is said to be “quantized”

Quantum Numbers Used to specify the properties of atomic orbitals and electrons in orbitals: 1. Principle quantum number (n) 2. Angular momentum number (l) 3. Magnetic quantum number (ml) 4. Spin quantum number(ms)

RULES FOR ELECTRON CONFIGURATION

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Chapter 6: The Periodic Table

Metals, Nonmetals, Metalloids https://www.brainpop.com/science/matterandchemistry/metals/

Metals Good conductors of heat and electric current Freshly cut piece of metal is luster (shiny) All metals are solid at room temperature except Mercury (Hg) Malleable and ductile Nonmetals Poor conductors of heat and electric current Most nonmetals are gases at room temperature (main components of air—nitrogen and oxygen) A few are solids (sulfur and phosphorus), Bromine (Br) is a liquid Brittle Metalloids Properties similar to those of metals and nonmetals (depending on conditions) Silicon is used in computer chips

GROUPS AND FAMILIES ON THE PERIODIC TABLE

Periodic Trends! Atomic Radius Electronegativity (ability to attract an electron) Ionization energy (energy required to remove an electron)

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Chapter 7&8: Bonding

What are valence electrons?

Ionic Bonding vs. Covalent Bonding