Exam 2: The Chemical Context of Life

Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates?

Which statement is True of all atoms that are anions?

Please refer to Figure 2.1 to answer the following questions. -Which drawing depicts the electron configuration of oxygen ( 16 8 O)?

In the term trace element, the modifier trace means

When two atoms are equally electronegative, they will interact to form

The following questions refer to Figure 2.3. -What results from the chemical reaction illustrated in Figure 2.3?

What results from an unequal sharing of electrons between atoms?

Which of the following would be regarded as compounds?

Please refer to Figure 2.1 to answer the following questions. -Which drawing depicts an atom that is inert or chemically unreactive?

Please refer to Figure 2.1 to answer the following questions. -Atoms whose outer electron shells contain eight electrons tend to

Oxygen has an atomic number of 8 and a mass number of 16. Thus, the atomic mass of an oxygen atom is

Refer to the following figure to answer the following questions. -The molecule shown here is the simplest of organic compounds. It is called

Use the information extracted from the periodic table in Figure 2.2 to answer the following questions. -Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to complete the valence shell of a fluorine atom?

The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound:

Use the information extracted from the periodic table in Figure 2.2 to answer the following questions. -What is the valence of an atom with six electrons in its outer electron shell?

Draw Lewis structures for each hypothetical molecule shown below, using the correct number of valence electrons for each atom. Determine which molecule makes sense because each atom has a complete valence shell and each bond has the correct number of electrons. Explain what makes the other molecules nonsensical, considering the number of bonds each type of atom can make. a. $\quad \mathrm { O } = \mathrm { C } - \mathrm { H }$ c. b. d.

Refer to the following figure to answer the following questions. -Which one of the atoms shown would be most likely to form an anion with a charge of -1?

How do isotopes of the same element differ from each other?

Use the information extracted from the periodic table in Figure 2.2 to answer the following questions. -How many electrons does an atom of sulfur have in its valence shell?

Use the information extracted from the periodic table in Figure 2.2 to answer the following questions. -How many neutrons are present in the nucleus of a phosphorus atom?