Chemistry Chapter 2 Flashcards

Questions and Answers

How many neutrons do potassium-39 and potassium-40 have, respectively?

Potassium-39 has 20 neutrons. Potassium-40 has 21 neutrons.

Which of the following statements is true of a neutral magnesium atom?

It has 10 protons, 10 electrons, and 10 neutrons.

It has 12 protons, 12 electrons, and 12 neutrons. (correct)

It has 12 protons, 10 electrons, and 12 neutrons.

It has 14 protons, 12 electrons, and 12 neutrons.

Which type of bond represents a weak chemical bond?

Hydrogen bond

An isotope of sodium (Na) has a mass number of 22. How many neutrons does it have?

11 Signup and view all the answers

Which of the following statements is not true?

Water is the most abundant atom in Earth's atmosphere. Signup and view all the answers

Using a pH meter, you find the pH of an unknown solution to be 8.0. How would you describe this solution?

Weakly basic Signup and view all the answers

Approximately how much of an increase in hydrogen ion concentration is there between tomato juice and lemon juice if lemon juice has a pH of 2.0 and tomato juice has a pH of 4.0?

An example of a monosaccharide is ___________.

fructose, glucose, and galactose. Signup and view all the answers

Cellulose and starch are examples of ___________.

polysaccharides Signup and view all the answers

Phospholipids are important components of ___________.

the plasma membrane of cells Signup and view all the answers

The monomers that make up proteins are called ___________.

amino acids Signup and view all the answers

Why are hydrogen bonds and van der Waals interactions necessary for cells?

They form weak associations between different molecules, providing structure and shape necessary for proteins and DNA. Signup and view all the answers

Why can some insects walk on water?

Because of the surface tension of water, which results from cohesion between water molecules. Signup and view all the answers

Explain why water is an excellent solvent.

Water molecules are polar, and they can surround and stabilize charged particles. Signup and view all the answers

Explain at least three functions that lipids serve in plants and/or animals.

They store energy, provide insulation, and are important components of cell membranes. Signup and view all the answers

Explain what happens if even one amino acid is substituted for another in a polypeptide chain. Provide a specific example.

A change in gene sequence can lead to a different amino acid being added, affecting protein structure. For example, sickle cell anemia results from a single amino acid substitution in hemoglobin. Signup and view all the answers

Study Notes

Neutrons in Potassium Isotopes

Potassium-39 contains twenty neutrons.
Potassium-40 contains twenty-one neutrons.

Neutral Magnesium Atom Characteristics

A neutral magnesium atom has 12 protons, 12 electrons, and 12 neutrons.

Weak Chemical Bond

Hydrogen bonds represent a weak type of chemical bond.

Neutrons in Sodium Isotope

An isotope of sodium with a mass number of 22 contains 11 neutrons.

Misconception About Water in Atmosphere

Water is not the most abundant atom in Earth's atmosphere.

pH Meter Reading

A solution with a pH of 8.0 is described as weakly basic.

Hydrogen Ion Concentration in Juices

Lemon juice (pH 2.0) has a hydrogen ion concentration approximately 100 times greater than that of tomato juice (pH 4.0).

Examples of Monosaccharides

Common monosaccharides include fructose, glucose, and galactose.

Polysaccharide Examples

Cellulose and starch are classified as polysaccharides.

Function of Phospholipids

Phospholipids are crucial components of the plasma membrane in cells.

Protein Building Blocks

Amino acids serve as the monomers that compose proteins.

Role of Hydrogen Bonds and Van der Waals Interactions

These weak interactions are essential for molecular associations, providing structural integrity to proteins and DNA, and contribute to the unique properties of water necessary for life.

Insect locomotion on Water

Certain insects can walk on water due to surface tension, which arises from cohesion among water molecules at the liquid-air interface.

Water as an Excellent Solvent

Water's polarity allows it to stabilize charged particles and prevent reassociation of ions, facilitating dissolution.

Functions of Lipids

Lipids serve multiple roles including energy storage, insulation, and as essential components of cell membranes (phospholipids and steroids).

Impact of Amino Acid Substitution on Polypeptides

Substituting even one amino acid can alter protein structure and function; for example, sickle cell anemia results from a single amino acid change in hemoglobin, leading to crescent-shaped red blood cells with serious health consequences.

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Description

Test your knowledge of important concepts from Chemistry Chapter 2 with these flashcards. Explore topics such as isotopes, atomic structure, and chemical bonds through various questions and answers. Enhance your understanding of the fundamental principles of chemistry.