Exam 2: Small Molecules and the Chemistry of Life

Refer to the table below. The table shows results from elemental analyses performed on a plant sample and a soil sample.These samples were dried prior to the analysis to remove all water.A scientist wants to use this information as the basis for identifying samples of unknown origin as either plant or soil material.Because running so many chemical tests can be time-consuming and expensive, she wants to limit future tests to one element.She would have the best chance of distinguishing between soil and plant material if she chose the element _______ for analysis.

In the history of the discovery of the parts of an atom, the neutron was discovered after the proton and electron.What property of a neutron made it more difficult than the proton or electron to discover?

In the periodic table, when elements are in the same vertical column, they share a similar

According to the periodic table, which element has the same number of outer shell (valence) electrons as oxygen?

The chemical properties of an element are determined by the number of _______ in the atom's valence shell.

Covalent bonds

Which element is the most chemically reactive?

An atom with 20 protons and 25 neutrons has an atomic number 20 and a mass number _______.

Which statement about water is false?

Every atom except _______ has one or more neutrons in its nucleus.

Which structure represents an isotope of hydrogen?

Refer to the figure below. For the solution containing a buffer, the pH range with greatest buffering capacity is

A cation has the opposite charge from a(n)

The water strider can skate along the surface of water because of a property of liquids called _______.

Refer to the figure below. Two molecules are shown.Where is it most likely that a hydrogen bond would form?

An ionic compound has the formula XCl₂, where X is a cation bonded through ionic attractions to two Cl⁻ anions.Sketch Bohr models to show how the ions interact to form such a compound.

Refer to the table below. The data support the claim that the strength of a covalent bond increases with the number of _______ that are shared between two atoms.

Refer to the figures below. A student is creating a diagram to illustrate the structure of water in an Arctic lake.The student has identified three zones of the lake to label.How should the smaller images be attached to the larger one?

What differentiates a strong acid from a weak acid?

What is the significance of Avogadro's number?