Unit #3 Study Guide
1. Elements are classified as _metals______, __metalloids______, and _nonmetals______.
2. What type of element is the greatest in number? __metals______
3. The _metalloids______are found along the stair – step line. They are sometimes referred to as _semiconductors______of electricity.
4. Classify the following characteristics as those of metals (M), nonmetals (NM) or metalloids (S).
__M___ good conductor of electricity _M____ malleable
__M___ good conductor of heat _M___ ductile
__NM___ dull and brittle _M____ shiny
__S___ semiconductors _NM____ most are gases
__M___ most are solids _NM poor conductor of electricity
5. All of the elements are organized into a table called the _periodic______table. The horizontal rows are called _periods______. The vertical columns are called __groups______.
6. All of the elements have their own chemical _symbol______which is usually the first letter or first and second letter of their name.
7. Which group of the periodic table is called the noble gases? _18______What is special about the noble gases?___unreactive______
8. Where are the metals located on the periodic table? _left of staircase______Where are the nonmetals located? ___right of staircase______
9. What is the name for group 1? _Alkali metals__ Group 2? _Alkaline Earth metals__ Groups 3 through 12? _transition metals_____ Group 17? ___Halogens______
10. The law of conservation of mass states that _mass__ is neither _created______nor __destroyed______during ordinary chemical reactions or physical changes.’
11. According to the law of conservation of mass, if element A has an atomic mass of 2 mass units and element B has a atomic mass of 3 mass units, what mass would be expected for compound AB? ___5______for compound A2B3? ____13______
12. The fact that a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound is known as the law of ___definite proportions______.
13. The law of multiple proportions states that if two or more different compounds are composed of the same two elements, then the _ratio______of the masses of the second _element______combined with the certain _mass______of the first element is always a _ratio______of small whole numbers.
14. Which two compounds are examples of the law of multiple proportions?
a. FeCl3 and Fe2(SO4)3 b. CO and CO2
c. O2 and O3 d. FeCl2 and Fe(NO3)2
15. According to the law of definite proportions, any two samples of KCl will have
a. the same mass
b. slightly different molecular structures but the same two elements
c. different densities
d. the same elements in the same proportions by mass
16. Who proposed an explanation for the law of conservation of mass, the law of definite proportions, and the law of multiple proportions? __John Dalton______
17. A summary of Dalton’s atomic theory can be explained in five statements. List those five statements.
18. Which aspects of Dalton’s atomic theory have proven to be incorrect? atoms are divisible and have isotopes (all atoms of the same element are not identical)
19. The nucleus of an atom contains at least one _postively____ charged particle called a _proton___ and one or more _neutral__ particles called neutrons. Surrounding the nucleus is a region occupied by _negatively__ charged particles called _electrons___.
20. Experiments with _cathode___ rays led to the discovery of the _electron______.
21. What is the significance of the deflection of cathode rays in Thomson’s experiment?
showed negatively charged particles were part of the atom
22. _Rutherford______discovered the nucleus with his gold foil experiment. Review specific aspects of this experiment.
23. Why are atoms electrically neutral?_____# protons = # electrons______
24. The short-range proton-neutron, proton-proton, and neutron-neutron forces that hold the nuclear particles together are referred to as __nuclear forces______.
25. Most of the volume of at atom is occupied by the __electron cloud______.
26. Most of the mass in the atom is concentrated in the __nucleus______.
27. The atomic number (Z) of an element is the number of _protons______in the __nucleus______of each atom of that element.
28. _Isotopes______are atoms of the same element that have different masses.
29. The mass number is the total number of _protons______and _neutrons______in the nucleus of an isotope.
30. An aluminum isotope consists of 13 protons, 13 electrons, and 14 neutrons. Its mass number is __27______.
31. How many protons, electrons, and neutrons are there in an atom of bromine-80? Protons _35__ electrons _35______neutrons __45______
32. How many protons, electrons, and neutrons are in an atom of carbon-13? Protons _6______electrons ___6______neutrons ___7______
33. Write the nuclear symbol for oxygen-16. ________
34. Write the hyphen notation for the element whose atoms contain 7 electrons and 9 neutrons. ___nitrogen-16______
35. The loss or gain of electrons results in the formation of an _ion______.
36. How many protons, electrons, and neutrons are in an S2- ion? _16,18, 16______
37. How many protons, electrons, and neutrons are in an Mg2+ ion? _12, 10, 12______
38. Average atomic mass is the weighted average of the _atomic______masses______of the naturally occurring __isotopes______of an element.
39. Is the atomic mass of an element on the periodic table the average atomic mass of the element’s isotopes or the mass of the most abundant isotope? average
40. Which element’s isotope is the standard for determining atomic mass? _carbon-12__
41. Review your polyatomic ions from quiz 1 and 2