Bsc 120 Test 1 Study Guide With Complete Solution!!

BSC 120 TEST 1 STUDY GUIDE WITH COMPLETE
SOLUTION!!
Which chemical element is the most common in your body (by weight?)
Answers :Oxygen (because there's a lot of it and Oxygen has the greatest molar
mass [~15.999] of HONC)
What is the smallest atom in the universe?


Answers :Hydrogen (because it's the smallest element and protons, electrons, and
neutrons are subatomic particles)
What is the molecular mass of a single water molecule?


Answers :18 (H = 1; O = 16; 2(1) + 16 = 18)
Which of the following molecules does not include hydrogen [What are the
chemical formulas for the following]? Carbon Dioxide, Ammonia, Water, and
Methane?


Answers :Carbon Dioxide (CO2)
Ammonia (NH3)
Water (H2O)
Methane (CH4)
Which of the following molecules includes carbon [What are the chemical
formulas for the following]? Water, Oxygen Gas, Methane, Ammonia, Table Salt?


Answers :Water (H2O)
Oxygen Gas (O2)
Methane (CH4)
Ammonia (NH3)

,Table Salt (NaCl)
Isotopes of the same element differ in the number of...


Answers :Neutrons (A different number of electrons is an ion; a different number
of protons is a different element)
How many electrons are needed to complete the outer shell of an oxygen atom?


Answers :2 (because it can form 2 covalent bonds because its outer shell is
missing 2 electrons before that level/layer is complete)
How many electrons are needed to complete the outer shell of a carbon atom?


Answers :4 (because it can form 4 covalent bonds because its outer shell is
missing 4 electrons before that level/layer is complete)
Which of the following atoms is most likely to lose an electron? O, C, N, Na, Cl


Answers :Na (because it has only 1 electron in its outer shell)
Which of the following holds together sodium and chlorine atoms in a crystal of
table salt? Covalent bond, ionic bond, isotopic bond, hydrogen bond, gravity


Answers :Ionic bond (because chlorine takes the electron from sodium; they both
become ions in the bond)
NOT Covelent because shared
NOT Isotopic because DNE
NOT Hydrogen because no hydrogen
NOT gravity because that's not how that force works
How many electrons are there in a single atom of hydrogen?

, Answers :1 (because there's 1 proton, and that keeps it neutral)
What is true for a negatively charged ion? "It is an atom that..."


Answers :Gained an electron
Which of the following is the most acidic pH? 2, 4, 7, 10?


Answers :2 (because lower pH = higher amounts of hydrogen ions = more acidic)
How many covalent bonds (maximum) does a single atom of N form?


Answers :3 (because it only has 3 open spaces left in its outer shell; also its third
in HONC)
How many covalent bonds (maximum) does a single atom of O form?


Answers :2 (because it only has 2 open spaces left in its outer shell; also it's
second in HONC)
Why are molecules of water in a bathtub held together by hydrogen bonds?


Answers :Because hydrogen bonds hold molecules of water together because of
the slight charge differences between H and O in different water molecules


Covalent bonds hold individual molecules of water together
How many covalent bonds (max) does a single atom of carbon form?


Answers :4 (because that's how many it needs; Also it's fourth in HONC)
How many atoms are there in a molecule of water?