1st Quarter Physical Science Reviewer

Questions and Answers

What is stellar nucleosynthesis?

The method of creating stars from gas and dust.

The process of forming elements within stars. (correct)

The emissions produced by stars during their lifetime.

The process by which stars explode.

What occurs during the CNO cycle in stars?

Helium is produced when carbon is present in hotter stars. (correct)

Helium is produced from hydrogen in cooler stars.

Carbon is produced as a byproduct of hydrogen fusion.

Oxygen is formed from the fusion of helium and hydrogen.

What defines the miscibility of two liquids?

Their ability to change states at different pressures.

Their ability to mix in all proportions. (correct)

Their ability to evaporate at the same temperature.

Their ability to dissolve in solid form.

What is the main characteristic of polar covalent bonds?

Electrons are shared unequally, leading to a charge distribution. Signup and view all the answers

What is the significance of the boiling point in liquids?

It is the temperature at which vapor pressure equals atmospheric pressure. Signup and view all the answers

What is viscosity a measure of?

The resistance of a liquid to flow. Signup and view all the answers

What distinguishes transuranic elements?

They are synthetic elements with atomic numbers higher than 92. Signup and view all the answers

What happens to vapor pressure as temperature increases?

Vapor pressure increases. Signup and view all the answers

What is the primary role of carbohydrates in the human body?

Serving as the primary energy source Signup and view all the answers

Which monosaccharide is commonly associated with fruits and honey?

Fructose Signup and view all the answers

What type of bond connects glucose molecules in starch?

α-1-4 glycosidic bond Signup and view all the answers

Which of the following disaccharides is formed from glucose and galactose?

Lactose Signup and view all the answers

What is a common characteristic of cellulose?

Contains β-1-4 glycosidic bonds Signup and view all the answers

How many amino acids are there that combine to form proteins?

20 Signup and view all the answers

Which term refers to proteins in their amino acid chain form?

Polypeptides Signup and view all the answers

What is a notable feature of glycogen compared to starch?

More highly branched structure Signup and view all the answers

Which protein has a high resistance to deformation and is primarily composed of β-pleated sheets?

Fibroin Signup and view all the answers

What is the main structural characteristic of collagen that contributes to its strength?

Triple helix structure Signup and view all the answers

What structural feature do hemoglobin and myoglobin share?

Both contain heme groups for oxygen binding Signup and view all the answers

Saturated fatty acids are characterized by which of the following features?

Are always solid at room temperature Signup and view all the answers

Which of the following correctly describes the classification of lipids?

Lipids include triglycerides and phospholipids Signup and view all the answers

Which protein is primarily involved in oxygen storage in muscles?

Myoglobin Signup and view all the answers

What is the main function of enzymes in biochemical reactions?

To lower the energy required for reactions to occur Signup and view all the answers

What type of structure do keratin proteins primarily exhibit?

Fibrous with α-helices and β-pleated sheets Signup and view all the answers

What components are found in a triglyceride?

Glycerol and three fatty acids Signup and view all the answers

What characterizes the two ends of a phospholipid?

One end is hydrophilic, and the other is hydrophobic Signup and view all the answers

What substance did Friedrich Miescher originally isolate from white blood cells?

Nuclein Signup and view all the answers

Which of the following is NOT a part of a nucleotide?

Lipids Signup and view all the answers

What is the primary sugar found in RNA?

Ribose Signup and view all the answers

Which nitrogenous base is found in RNA but not in DNA?

Uracil Signup and view all the answers

What role do nucleic acids play in living organisms?

Storage, transfer, and expression of genetic information Signup and view all the answers

How do the sequences of base pairs in DNA differ among organisms?

They vary unique to every organism Signup and view all the answers

What is the molar heat of vaporization (ΔHvap)?

The energy required to vaporize 1 mole of a liquid at a given temperature. Signup and view all the answers

Which type of intermolecular force is characterized by the attraction between oppositely charged ions?

Ion-ion interaction Signup and view all the answers

What defines a polar molecule?

It has both a partial positive pole and a partial negative pole. Signup and view all the answers

Which type of intermolecular force is considered a very strong dipole-dipole interaction?

Hydrogen bonding Signup and view all the answers

What is true about dispersion forces?

They are present in all molecules, including nonpolar ones. Signup and view all the answers

Which of the following forces has the lowest strength?

Dispersion forces Signup and view all the answers

How are ion-ion interactions typically described?

Strong, with high melting and boiling points. Signup and view all the answers

What is the average strength of a dipole-dipole interaction?

4 kJ/mol Signup and view all the answers

Study Notes

Important Concepts in Physical Science

Stellar Nucleosynthesis: Formation of elements within stars through nuclear reactions.
CNO Cycle: Process in stars hotter than 15 million K, using carbon to produce helium.
Miscibility: Ability of two liquids to mix in all proportions.
Solubility: Capacity of a solute to dissolve in a solvent.
Electronegativity: Atom’s tendency to attract shared electrons in a chemical bond.
Molecule: Group of two or more atoms connected by a chemical bond.
Polarity: Distribution of electric charge within atoms or molecules.

Synthesis of Elements

Cyclotron: Device enabling artificial transmutation of elements.
Transuranic Elements: Synthetic elements with atomic numbers greater than uranium (Z > 92).
Superheavy Elements: Elements beyond atomic number 103, produced by bombarding heavy targets.

Polarity of Molecules

Polar Covalent Bonds: Unequal sharing of electron pairs; electronegativity difference of 0.5 – 1.9.
Non-Polar Covalent Bonds: Equal sharing of electron pairs; electronegativity difference < 0.5.
Ionic Bonds: Significant electronegativity difference (> 2.0) indicating full electron transfer.

Properties of Liquids

Surface Tension: Phenomenon allowing some objects to float on liquids due to cohesive forces.
Viscosity: Measure of a liquid's resistance to flow; higher viscosity indicates slower flow.
Vapor Pressure: Pressure from molecules escaping the liquid; increases with temperature.
Boiling Point: Temperature at which vapor pressure equals external pressure; normal boiling point of water is 100°C.
Molar Heat of Vaporization: Energy needed to vaporize one mole of liquid at standard conditions.

Intermolecular Forces

Intermolecular Forces: Attractions between molecules, distinct from intramolecular forces (within molecules).
Ion-Ion Interaction: Strong attractions between oppositely charged ions; results in high melting/boiling points.
Dipole-Dipole Interaction: Weaker forces between polar molecules with partial charges.
Hydrogen Bonding: Strong dipole-dipole interaction between hydrogen and electronegative atoms (F, O, N).
Dispersion Forces (London Forces): Present in all molecules; weakest type and significant in nonpolar molecules.

Biological Macromolecules

Carbohydrates

Derived from Latin "saccharum"; primary energy source for humans.
Monosaccharides: Simple sugars (e.g., glucose, galactose, fructose) with the formula C6H12O6.
Disaccharides: Two monosaccharides joined (e.g., maltose, sucrose, lactose).
Polysaccharides: Many monosaccharides (e.g., starch, glycogen, cellulose).
- Starch: Storage form of glucose in plants.
- Glycogen: Storage form in animals; highly branched.
- Cellulose: Structural material in plant cell walls; indigestible by humans.

Proteins

Composed of amino acids; perform various structural and functional roles.
Amino Acids: 20 types; joined by peptide bonds to form proteins (polypeptides).
Keratin: Structural protein in hair and nails; includes α-helix and β-pleated sheets.
Fibroin (Silk): Strong natural fiber; composed primarily of β-pleated sheets.
Collagen: Major protein in connective tissues, has a triple helix structure for strength.

Enzymes

Act as catalysts to speed up chemical reactions; highly specific to substrates.

Examples of Enzymes

Myoglobin: Stores oxygen in muscles; contains a heme group.
Hemoglobin: Transports oxygen in blood; composed of four sub-units.

Lipids

Grouped by hydrophobic properties; include waxes, triglycerides, phospholipids, and steroids.
Fatty Acids: Long-chain carboxylic acids; can be saturated (single bonds) or unsaturated (double bonds).
Triglycerides: Composed of glycerol and three fatty acids; common fats and oils.
Phospholipids: Composed of glycerol, two fatty acids, and a phosphate group; critical for cell membranes.

Nucleic Acids

Essential for storage and transfer of genetic information; consist of DNA and RNA.
Nucleotide Components: Nitrogenous base, five-carbon sugar, phosphate group.
DNA vs. RNA: DNA has deoxyribose sugar and includes bases A, G, C, T; RNA has ribose and includes A, G, C, U.

Genetic Information

Unique DNA sequences determine the synthesis of proteins, influencing cellular processes.

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Description

Prepare for your 1st quarter exams in Physical Science with this informative quiz. It covers essential terms such as stellar nucleosynthesis, electonegativity, and the CNO cycle, helping you grasp key concepts. Test your understanding and get ready to excel in your studies!