Matter and Atoms Overview
42 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the overall equation for photosynthesis?

  • 6H2O + C6H12O6 → 6O2 + 6CO2
  • C6H12O6 + 6O2 → 6CO2 + 6H2O
  • 6CO2 + 6O2 → 6H2O + C6H12O6
  • 6CO2 + 6H2O → C6H12O6 + 6O2 (correct)

Which property of water allows it to support life by maintaining temperature?

  • Solvency
  • High heat of vaporization
  • High heat capacity (correct)
  • High surface tension

What type of bond forms between the oxygen atom of one water molecule and the hydrogen atom of another?

  • Nonpolar covalent bond
  • Hydrogen bond (correct)
  • Ionic bond
  • Polar covalent bond

What percentage of water content is typically found in all organisms?

<p>70–90% (A)</p> Signup and view all the answers

Which of the following is NOT a property of water?

<p>Magnetism (C)</p> Signup and view all the answers

What causes the atoms in a water molecule to share their electrons unequally?

<p>Electronegativity of oxygen (D)</p> Signup and view all the answers

Which property of water is responsible for its ability to dissolve many substances?

<p>Solvency (D)</p> Signup and view all the answers

What phenomenon allows water to form from hydrogen bonds?

<p>Surface tension (C)</p> Signup and view all the answers

What is the maximum number of electrons that can occupy the second electron shell of an atom?

<p>8 (D)</p> Signup and view all the answers

Carbon-14 dating can determine the age of organic materials up to approximately how many years?

<p>60,000 years (A)</p> Signup and view all the answers

What happens to carbon-14 in an organism after it dies?

<p>It changes into other atoms. (B)</p> Signup and view all the answers

Which of the following correctly describes valence in an atom?

<p>The number of electrons in the outermost shell. (A)</p> Signup and view all the answers

The octet rule states that atoms are most stable when they have how many electrons in their outer shell?

<p>8 (D)</p> Signup and view all the answers

What do orbitals represent in an atom?

<p>The probable locations of electrons. (B)</p> Signup and view all the answers

In atoms with more than two shells, what is the primary factor affecting the stability of the outer shell?

<p>Having a full outer shell of eight electrons. (C)</p> Signup and view all the answers

Which of the following statements about chemical properties of atoms is correct?

<p>They are largely influenced by the arrangement of electrons. (A)</p> Signup and view all the answers

What property of water allows it to dissolve many substances?

<p>Polarity and hydrogen bonding (B)</p> Signup and view all the answers

Which type of molecules are attracted to water?

<p>Hydrophilic (B)</p> Signup and view all the answers

How does water's adhesion property assist in nature?

<p>It helps in the transportation of water within plants. (D)</p> Signup and view all the answers

What occurs when NaCl is dissolved in water?

<p>The salt dissociates into ions. (A)</p> Signup and view all the answers

What contributes to the high surface tension of water?

<p>Hydrogen bonding between water molecules (B)</p> Signup and view all the answers

Which property of water explains why it moves up a tree from the roots to the leaves?

<p>Cohesion (D)</p> Signup and view all the answers

Hydrophobic molecules are characterized by their ability to:

<p>Repel water. (B)</p> Signup and view all the answers

What is the general process by which molecules separate into ions, atoms, or radicals called?

<p>Dissociation (C)</p> Signup and view all the answers

What property of water allows it to absorb heat without significantly changing temperature?

<p>Hydrogen bonding (A)</p> Signup and view all the answers

What happens to the temperature of water when it absorbs heat?

<p>It rises and falls slowly (B)</p> Signup and view all the answers

Why does ice float on water?

<p>Water expands as it freezes, making ice less dense (C)</p> Signup and view all the answers

What energy change occurs as water evaporates?

<p>Cooling occurs due to heat dispersion (B)</p> Signup and view all the answers

What role does ice play in aquatic environments?

<p>It acts as a thermal insulator (C)</p> Signup and view all the answers

What is the primary function of buffers in the body?

<p>To keep pH within normal limits by neutralizing excess H+ and OH- (A)</p> Signup and view all the answers

What is the normal pH range of blood in a healthy individual?

<p>7.35 – 7.45 (C)</p> Signup and view all the answers

What condition can result from the body's inability to buffer excess H+ ions?

<p>Acidosis (A)</p> Signup and view all the answers

Which disease is associated with an increased risk of acidosis due to buffering failure?

<p>Congestive heart failure (C)</p> Signup and view all the answers

What can ultimately happen if acidosis is left untreated?

<p>Organ failure and death (B)</p> Signup and view all the answers

What ions are produced when water dissociates?

<p>Hydrogen ions and hydroxide ions (C)</p> Signup and view all the answers

Which solution is considered acidic based on pH?

<p>pH of 5 (A)</p> Signup and view all the answers

Which of the following acids releases hydrogen ions when dissolved?

<p>Hydrochloric acid (B)</p> Signup and view all the answers

A solution with a pH of 6 is classified as what?

<p>Acidic (C)</p> Signup and view all the answers

What happens to the concentration of hydroxide ions in a basic solution?

<p>It is higher than that of hydrogen ions (D)</p> Signup and view all the answers

Which of the following describes the pH scale?

<p>Ranges from 0 to 14 (B)</p> Signup and view all the answers

Which solution is classified as basic?

<p>Milk of magnesia (C)</p> Signup and view all the answers

What does a pH of 7 indicate about a solution?

<p>It is neutral with equal H+ and OH− ions (A)</p> Signup and view all the answers

Flashcards

Carbon-14 Dating

A method to estimate the age of organic material up to about 60,000 years old by measuring the remaining carbon-14 atoms.

Carbon-14

A radioactive form of carbon that's absorbed by living things and decays over time.

Electron Shells

Energy levels where electrons orbit the atom's nucleus.

Electron Orbitals

Areas of probable electron location.

Signup and view all the flashcards

Octet Rule

Atoms tend to gain, lose, or share electrons to achieve 8 electrons in their outermost shell.

Signup and view all the flashcards

Valence Shell

The outermost electron shell of an atom.

Signup and view all the flashcards

Valence

The number of electrons in an atom's outermost shell.

Signup and view all the flashcards

Electron arrangement

The way electrons are distributed in shells around an atom's nucleus.

Signup and view all the flashcards

Photosynthesis equation

The process where plants use carbon dioxide, water, and sunlight to produce glucose (sugar) and oxygen.

Signup and view all the flashcards

Glucose

A type of sugar produced during photosynthesis.

Signup and view all the flashcards

Water's importance to life

Water is the most essential molecule for life, making up a significant portion of all organisms.

Signup and view all the flashcards

Polar covalent bond (water)

In water's structure, oxygen pulls shared electrons more strongly than hydrogen, causing slight charges within the molecule.

Signup and view all the flashcards

Hydrogen bond (water)

Attractive forces between slightly positive hydrogen atoms of one water molecule and slightly negative oxygen atoms in another.

Signup and view all the flashcards

Water's solvent property

Water can dissolve many substances because of its polar nature.

Signup and view all the flashcards

Water's cohesion

The tendency of water molecules to stick together.

Signup and view all the flashcards

Water's high heat capacity

Water can absorb a lot of heat energy without a large temperature change.

Signup and view all the flashcards

Solvent

A substance that dissolves another substance (solute).

Signup and view all the flashcards

Hydrophilic

Molecules attracted to water.

Signup and view all the flashcards

Hydrophobic

Molecules not attracted to water.

Signup and view all the flashcards

Dissociation

The separating of molecules or compounds into smaller parts like atoms or ions.

Signup and view all the flashcards

Cohesion

Water molecules clinging to each other.

Signup and view all the flashcards

Adhesion

Water molecules clinging to other polar surfaces.

Signup and view all the flashcards

Surface tension

Water's high ability to resist external forces.

Signup and view all the flashcards

Water as a transport system

Water's ability to transport substances because of cohesion and adhesion.

Signup and view all the flashcards

High heat capacity of water

Water absorbs significant heat without a large temperature change due to hydrogen bonding between water molecules.

Signup and view all the flashcards

High heat of vaporization

A large amount of energy is needed to break hydrogen bonds, allowing water to evaporate, and cooling the surrounding environment.

Signup and view all the flashcards

Ice less dense than water

Water expands when it freezes, making ice less dense than liquid water, causing it to float.

Signup and view all the flashcards

Water's expansion on freezing

Water molecules arrange themselves in a lattice structure when freezing, increasing the volume (space taken up).

Signup and view all the flashcards

Ice insulation in water

Ice floating on water insulates the water below, allowing life to exist in cold temperatures.

Signup and view all the flashcards

Water Dissociation

Water molecules break apart into hydrogen ions (H+) and hydroxide ions (OH-) in a reversible reaction.

Signup and view all the flashcards

Acidic Solution

A solution with a higher concentration of hydrogen ions (H+) than hydroxide ions (OH-), resulting in a pH below 7.

Signup and view all the flashcards

Basic Solution

A solution with a higher concentration of hydroxide ions (OH-) than hydrogen ions (H+), resulting in a pH above 7.

Signup and view all the flashcards

pH Scale

A scale ranging from 0 to 14 used to measure the acidity or alkalinity of a solution. pH below 7 is acidic, pH above 7 is basic, and pH of 7 is neutral.

Signup and view all the flashcards

What does pH measure?

pH measures the concentration of hydrogen ions (H+) in a solution.

Signup and view all the flashcards

What is the pH of a neutral solution?

A neutral solution has a pH of 7, indicating an equal concentration of hydrogen ions (H+) and hydroxide ions (OH-).

Signup and view all the flashcards

Acidic vs. Basic

Acids release H+ or take up OH-, while bases take up H+ or release OH-. This determines the pH of a solution.

Signup and view all the flashcards

pH and H+ Concentration

Lower pH values correspond to higher concentrations of H+ ions, indicating a more acidic solution.

Signup and view all the flashcards

What are buffers?

Buffers are chemicals or combinations of chemicals that keep the pH of a solution within normal limits. They resist changes in pH by taking up excess hydrogen ions (H+) or hydroxide ions (OH-)

Signup and view all the flashcards

How does pH relate to blood?

The pH of blood is normally around 7.35-7.45, slightly alkaline. This is maintained by buffer systems within the body.

Signup and view all the flashcards

What is acidosis?

Acidosis occurs when the body cannot buffer excess hydrogen ions (H+). This causes the blood pH to become too acidic.

Signup and view all the flashcards

How can acidosis be caused?

Conditions like congestive heart failure or diabetes can disrupt the body's ability to buffer H+ ions, leading to acidosis.

Signup and view all the flashcards

What are the potential consequences of acidosis?

Uncontrolled acidosis can be fatal. If left untreated, it can cause organ damage and ultimately death.

Signup and view all the flashcards

Study Notes

Matter and Atoms

  • Matter is anything that occupies space and has mass.
  • Matter exists as solids, liquids, gases, or plasma.
  • Matter is composed of elements.
  • An element cannot be broken down into other substances by ordinary chemical means.
  • Only 92 elements occur naturally.
  • Four elements—carbon, hydrogen, oxygen, and nitrogen—make up about 96% of the body weight of most living organisms.

Where Elements Come From

  • Normal chemical reactions do not produce elements.
  • Heavier elements, like iron, are created in supernova explosions.
  • Supernova explosions scatter heavier elements into space, which then become parts of planets.

Atomic Structure 1

  • Atoms are the basic units of elements.
  • Atoms cannot be subdivided into smaller substances without losing their properties.
  • Atoms are composed of subatomic particles:
    • Protons (positively charged)
    • Neutrons (no charge)
    • Electrons (negatively charged)
  • Protons and neutrons are found in the nucleus.
  • Electrons are found outside the nucleus in orbitals.

Atomic Structure 2

  • Atomic symbol: represents the atom/element
  • Examples: H (hydrogen), Na (sodium)
  • Mass number: sum of protons and neutrons (electrons have negligible mass)

Atomic Number

  • All atoms of an element have the same number of protons.
  • The atomic number equals the number of protons and electrons in a neutral atom.

Periodic Table

  • Elements' chemical and physical characteristics recur in a predictable manner.
  • Elements are arranged in periods (rows) and groups (columns) in the periodic table.

Isotopes

  • Atoms of the same element can differ in the number of neutrons.
  • Isotopes have the same number of protons but different numbers of neutrons (and thus different mass numbers).
  • Some isotopes are unstable and decay, emitting radiation.
  • Radioactive isotopes behave very similarly to stable isotopes, but can be used as tracers or to sterilize equipment.

Arrangement of Electrons in an Atom

  • Electrons are constantly moving.
  • Electron shells are useful for models of atoms with energy levels.
  • Each shell contains a certain number of electrons.
  • Orbitals are pathways in which electrons rotate around the nucleus.

Bonds and Molecules

  • Molecules result from combinations of two or more atoms.
  • Compounds are molecules composed of two or more different elements.
  • Atoms can share, donate, or accept electrons to form chemical bonds.

Types of Chemical Bonds

  • Chemical bonds form when two or more atoms share, donate, or accept electrons.
    • Ionic bonds: result from electron transfers between atoms, forming ions with opposite charges.
    • Covalent bonds: result from electron sharing between atoms to complete their outer electron shells.
    • Hydrogen bonds: occur when a hydrogen atom attracted to electronegative atoms (like oxygen or nitrogen).

Chemical Formulas and Reactions

  • Chemical formulas show the elements and the relative number of atoms in a compound.
  • Balanced chemical equations have the same number of each type of atom on both sides.
  • Reactants are substances that participate in a chemical reaction.
  • Products are the substances produced by a chemical reaction.

Water's Importance to Life

  • Life began in water.
  • Water is the most important molecule on Earth, making up 70-90% of most organisms.
  • Water's properties (solvency, cohesion, adhesion, high surface tension, high heat capacity, high heat of vaporization, and varying density) are crucial for life.

Acids and Bases

  • Water dissociates into hydrogen ions (H⁺) and hydroxide ions (OH⁻).
  • Acidic solutions have a high concentration of H⁺ ions, while basic solutions have a low concentration of them and a high concentration of OH⁻.
  • The pH scale measures the concentration of H⁺ ions in a solution.
  • Buffers are substances that maintain a relatively stable pH.

pH and pH Scale

  • pH is the scale used to measure hydrogen ion concentration.
  • The pH scale ranges from 0 to 14, with 7 being neutral.
  • An acidic solution has a low pH, while an alkaline (basic) solution has a high pH.

Buffers and pH

  • Buffers resist changes in pH by absorbing or releasing H+ or OH- ions.
  • The human body uses buffers to maintain a relatively constant blood pH.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Chapter 2: The Chemical Basis of Life PDF

Description

Explore the fundamental concepts of matter and atoms in this quiz. Learn how elements combine to form matter and the origins of elements in the universe. Test your understanding of atomic structure and the role of subatomic particles.

More Like This

Chemistry Basics and Atomic Structure
14 questions

Chemistry Basics and Atomic Structure

PureAnemone avatar
PureAnemone
Chemistry Basics: Matter and Atomic Structure
3 questions

Chemistry Basics: Matter and Atomic Structure

TrustingParabola avatar
TrustingParabola
Chemistry: Matter and Atoms
37 questions

Chemistry: Matter and Atoms

DignifiedLarch122 avatar
DignifiedLarch122
Chemistry Chapter: Matter and Atomic Structure 2.2
50 questions

Chemistry Chapter: Matter and Atomic Structure 2.2

ExhilaratingOrientalism7564 avatar
ExhilaratingOrientalism7564
Use Quizgecko on...
Browser
Open
Browser
Browser