Biol Chapter 2 Review

If you were to create a planet capable of supporting life forms similar to those on earth, what elements would be necessary to include? Select all that apply.

- Helium -Glucose

Fill in the blanks with the appropriate word or value.

- The atomic mass of an atom is a relative measure of its mass compared to other atoms. - One Dalton is approximately the mass of one proton or a hydrogen atom. - A mole of a substance contains the same number of particles as there is in 12g of carbon. - 12g of carbon = 1 mole. - 1g of hydrogen = 1 mole. - 7g of lithium = 1 mole.

Complete the sentences describing the properties of water that contribute to its role as a solvent in living organisms.

- The unequal sharing of electrons between the oxygen and hydrogen atoms within a water molecule makes water a polar molecule. - As a result of the electron configuration of a water molecule, water is a great solvent because water can break up and surround a solute, as long as it is not nonpolar, dissolving it into solution. - The reason water behaves in this manner is because the positive charge on the hydrogen end of the water molecule is attracted to the negative charge of a polar molecule, while the negative charge of the oxygen end of the water molecule is attracted to the positive side of a polar molecule.

Fill in the blanks and place the sentences in order to most accurately describe the process by which water is transported from the ground to the branches and leaves of a tree.

- Trees take up water from their roots. Water must travel against gravity up to all of the branches and leaves. - As water evaporates from the pores of the leaves, more water is pulled up from below resulting in a constant supply of water moving up through the vessels of a plant. - The cohesion of water molecules, resulting from the hydrogen bonds between water molecules, causes a movement of the water through the plant's vessels, as it moves up from the roots.

Water (H₂O) is critical to sustain life. One of its major roles is creating and breaking bonds in chemical reactions. Other significant roles of water include

- composing up to 30% of the human body. - the protection and support of organs. - acting as the medium for white blood cell formation.

Mark the following statements as true or false. 1. The bonds between water molecules are stable. 2. As temperature drops the bonds between water molecules are less likely to break. 3. Ice is denser than liquid water at all temperatures. 4. The polar covalent bonds between hydrogen and oxygen atoms within a water molecule create slight positively and negatively charged ends to the molecule. 5. The fluid nature of water is due to hydrogen bonds continually breaking and reforming. 6. A hydrogen atom of one water molecule binds via a hydrogen bond to a hydrogen atom of another water molecule. 7. Bonds between water molecules are stronger than the bonds between the atoms within a water molecule.

1. False 2. True 3. False 4. True 5. True 6. False 7. False

Mark the following statements as true or false concerning water's relevance to living systems. 1. Ten to twenty percent of the body weight in humans is from water. 2. Water is the universal solvent, transporting dissolved substance in bodily fluids. 3. Water bathes organs in fluid, which provides protection and support. 4. The high specific heat of water means that we only lose a small amount of heat when the sweat on our skin evaporates. 5. Water plays a major role in our bodies' chemical reactions. 6. Water plays a much more important role in plants than in animals, due to the role of water in photosynthesis.

1. False 2. True 3. True 4.False 5. True 6. False

Match the following pairs of atoms with the statement that correctly describes both atoms in the pair. 1. They have the same number of electrons in their outermost shells. 2. They have two electron shells. 3. Their outermost electron shell is full. 4. They have one electron shell. 5. They have three electron shells.

1. Nitrogen & Phosphorus 2. Carbon & Nitrogen 3. Helium & Argon 4. Hydrogen & Helium 6. Sodium & Chlorine

Carbon 12, 13, and 14 are isotopes of the same element. They share the same place on the periodic table but possess varying numbers of neutrons. If carbon 12 has 6 protons, how many neutrons will carbon 14 have?

8.

For each chemical reaction indicate whether the first reactant on the left side of the equation is an acid or a base.

Acid ∙ HCl → H⁺ + Cl⁻ ∙ H₂CO₃ → H⁺ + HCO₃⁻ Base ∙ NaOH → Na⁺ + OH⁻ ∙ NH₃ + H₂O → NH₄⁺ + OH⁻

Adding NH₃ (ammonia) to water makes NH₄⁺. What will be the general pH of this new solution, and what will happen to the ion concentrations?

Alkaline; decreased H⁺ ions and increased OH⁻

For each statement indicate which type of bond is being described. Covalent bonds, iconic bonds, and hydrogen bonds.

Covalent Bonds - Strong chemical bond due to the sharing of electrons - Bonds between hydrogen and oxygen atoms within a water molecule Iconic Bonds - Electrons are transferred between two atoms creating positively and negatively charged atoms, which are then attracted to one another - Na⁺ + Cl⁻ → NaCl Hydrogen Bonds - Bonds between charged molecules or portions of a molecule - Weak attraction between slightly charged parts of molecules, which are readily broken and reformed - Bonds between water molecules

If the products in a chemical equation include H₂O, what specific type of reaction is occurring? Is a polymer being made or broken down in this equation?

Dehydration; polymers are made.

When H₂O is added to a compound in a chemical equation, a new compound can be formed via what type of reaction?

Hydrolysis.

What molecules are needed to complete the missing parts of this dehydration synthesis reaction? C₆H₁₂O₆ + C₆H₁₂O₆ → _______ + __________

H₂O + C₁₂H₂₂O₁₁.

Which two elements show similarities in the pattern of chemical bonding?

Lithium and Sodium.

Based on the information contained in the periodic table, which compound would have the greatest molecular mass

MgCl₂.

6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + O₂ is an example of a chemical reaction. What is occurring during this reaction?

Substances are changed into other substances by the making or breaking of chemical bonds.

When two atoms are bonded together via electrons, and one of those atoms has a greater pull upon the electrons shared, the bond formed would be

a polar covalent bond.

A polar covalent bond is created when ______

bonded atoms have unequal pull on the shared electron, so that the electron spends more time around one atom than the other.

Stable blood serum has a pH of around 7.4. The release of bicarbonates as a buffer to maintain this pH in a body with high hydrogen levels would cause the pH to move

from acidic to slightly alkaline.

The best summary of the properties of water is

less dense at 0°C than at room temperature, ideal solvent for biological molecules, absorbs considerable heat energy without raising temperature, and high percentage of hydrogen bonds.

The property of water that allows the basilisk lizard to run across its surface is

the high surface tension caused by the polar qualities of water.