ENVS Exam 2
If a neutral element has the following chemical symbol, how many electrons does it have? 18/6 O
6
The typical carbon atom is described in the periodic table by the accompanying box. How many protons are in a typical oxygen atom?
8
If a neutral element has the following chemical symbol, how many electrons does it have? 235/92 U
92
Which of the following is not made from long chains of glucose?
?
What is an organic compound?
A molecule that contains carbon bonded to other elements
Which of the following elements will most likely not form an ion at all?
Ar
Why is life based on carbon-based molecules?
Because a single carbon can bond with up to four other atoms
Which is not one of the four atoms that make up the bulk of living organisms?
Calcium
What are the four classes of large organic molecules important to life on Earth?
Carbohydrates, proteins, lipids, and nucleic acids
Organic compounds are distinguished by molecules that contain ________ bonded to other elements.
Carbon
The bond in which bonded atoms share electrons is called a(n) ________.
Covalent Bond
Which of the following is the correct electron dot structure for chlorine (atomic no. = 17)?
D (7 dots)
Which of the following represents a simple sugar (also called a monosaccharide)?
Glucose
What is the valence shell?
It is the outermost shell of electrons in an atom.
Which of the following elements will most likely form an ion with a +1 charge?
Na
Which would have the highest concentration of C-H bonds?
Saturated Fat
Why are the atomic masses listed in the periodic table not whole numbers?
The atomic masses are average atomic masses.
Select the most complete explanation of what the pH scale measures.
The concentration of hydrogen ions in a solution
What are isomers?
Two molecules that have the same atoms arranged differently
Why can't we see atoms?
We see with light energy and the wavelength is larger than the object and so it is not reflected.
Does it make sense to say that a textbook is about 99.9 percent empty space?
Yes. A textbook like all material things is made up of atoms, which are considered to be 99.9 percent empty space.
Something with a pH of 5 would be ________.
acidic
What are the monomers of proteins?
amino acids
The following statement describes which subatomic particle best? It is located outside of the nucleus.
an electron
If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element?
atomic mass, 99 amu; technetium
Which of the following elements is a halogen?
chlorine (Cl)
Which of the following would not be considered matter?
light
How many electrons are there in the third shell of sodium, Na (atomic number 11)?
one
During a chemical reaction, atoms are ________.
rearranged
When a gas is changed to a liquid phase, the gas
releases energy