Core Test Review

1. Core Test Review

2. Standard 1.1 • Elements in the universe have one common origin. Evidence to show this is that all matter discovered has the same elements in their structure. • The only way to observe matter in distant stars is to view the spectrum of light from distance stars. • Heavier elements are formed as lighter elements fuse together under very energetic conditions. (fusion)

3. Standard 1.2 • Relative masses and charges of sub atomic particles • Electron 1/2000th of the proton, negative charge • Proton 1, and a charge of +1 • Neutron 1, no charge

4. 1.2 continued • Avogadro’s number- 6.02 x 10^23 • There are that many atoms in a mole of an element. A mole is measured by the molar mass. The mass on the periodic table for an element is the mass of 6.02 x 10^23 atoms of that element

5. Standard 1.3 • Reactivity of elements on the periodic table • Reactivity increases as we move down the periodic table for METALS • Reactivity increases as we move up the periodic table for NON-METALS

6. 1.3 continued • Isotopes- same elements with different numbers of NEUTRONS • Atomic mass is the ONLY thing that changes for an isotope • The rest of this standard covers the various properties of the elements and how they are organized on the periodic table. Remember groups or families of elements have similar properties.

7. Standard 2.1 • Quantum theory- the study of electron movement • Energy is absorbed when electrons move to a higher energy level • Energy is released when electrons return to their original levels • The greater the fall or jump the greater the energy change • High energy changes lead to brighter colors in the em spectrum (Blue or violet) • Low energy changes lead to lower colors (red or orange) • RPYGBIV

8. Standard 2.2 • Half life- how long it takes for half of a substance to decay • Mass / 2^number of half lifes • Gamma- high energy, massless, chargeless radiation • Beta- middle energy, charge and mass equal to an electron • Alpha- low energy, mass of 4, positively charged

9. Standard 3.1 • Non-metals have high electronegativities • Metals have low electronegativities • Metals conduct because of mobile electrons • Metals form positive ions (loose negative electrons) • Non-metals form negative ions (gain negative electrons) • Valence electrons are outer most electrons. The family number matches the number of ve’s.

10. Standard 3.2 • This section is where naming comes in so try to remember the names of basic polyatomic ions like • OH- Hydroxide • SO4-2 Sulfate • NO3- Nitrate • Also remember that combined elements have different properties than uncombined elements

11. Standard 3.3 • Molecular shapes and polarity will be tested • Water is bent and polar • Ammonia us trigonal pyramidal and polar • Methane is tetrahedral and non-polar

12. 3.3 continued • Bond types • Ionic are between a metal and a non-metal example- NaCl • Polar are between two non-metals that do not share equally. Check to see if the elements are very close to each other on the periodic table, it they are not they are polar. (not including C and H) example- NH3 • Non-polar are two non metals that are very close to each other on the PT. example- Cl2

13. 3.3 continued • Hydrogen bonding • Accounts for the special characteristics of water • Unusually high melting point • Unusually high boiling point • Solid is less dense (floats) in the liquid • Water molecules stick together (cohesion)

14. Standard 4.1 • Review your evidences of chemical reactions • Gas • Unexpected color change • Temperature change (heat) • Light • Precipitate • Electrical potential created

15. 4.1 continued • This standard test basic knowledge of chemical reactions • Neutralization reaction is between and acid and a base producing water and a salt • Combustion produces water and carbon dioxide • Review types of reactions • composition • Decomposition • Single and double replacement

16. Standard 4.2 • This is a more difficult standard, but we usually do well. • Balanced reaction means same number of atoms on both sides of arrow • Endothermic- heat taken in • Exothermic- heat is released • The heat term will be listed as a value like 14.5 kj • math

17. Section 5.1 • Easiest standard, factors affecting reaction rate • Increase temp leads to more and more energetic collisions • Increased concentration leads to more collisions • Reducing particle size leads to more surface area per particle

18. 5.1 continued • Catalyst lower activation energy ONLY • Endothermic and exothermic reaction graphs • Be ready to see graphs in these questions

19. Section 5.2 • Equilibrium and Le Chatlier’s principle • Reverse reactions can go both ways • At equilibrium the forward and reverse rates are equal • Add away • Take I stay • These work for heat and concentration • Increased pressure will lead to a shift to the side with the least # of moles • Decreased pressure will lead to a shift to the side with the most # of moles

20. Section 6.1 • Molarity= moles / liters • Do the math! • Solute is the substance dissolved • Solvent is the liquid • Heat, agitation, and decreased particle size help increase the rate of dissolution

21. Standard 6.2 • Colligative properties • The properties of a solution will be different than the properties of the pure substances • Elevated boiling point • Depressed freezing point • Salt on roads is best example

22. Standard 6.3 • Acids and bases- the concentration of H+ determines the acidity • High concentration of H+ Acid • Low concentration of H+ Base • Low pH Acid • High pH base • 7 pH neutral

23. 6.3 continued • Titration- the addition of a known solution to neutralize an unknown solution. • Math- multiply the pair and divide by the loner • We use titrations to determine the concentration of unknowns acids or bases