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Questions and Answers
What is the basic unit of matter?
What is the basic unit of matter?
Chemical properties of matter do not change the identity of the substance.
Chemical properties of matter do not change the identity of the substance.
False
What is the term for a combination of two or more atoms?
What is the term for a combination of two or more atoms?
Molecule
Matter can neither be ______ nor destroyed, but only transformed.
Matter can neither be ______ nor destroyed, but only transformed.
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Match the properties with their definitions:
Match the properties with their definitions:
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Which law states that the composition of a substance is the same regardless of where it is found?
Which law states that the composition of a substance is the same regardless of where it is found?
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Physical changes in matter result in a new substance being formed.
Physical changes in matter result in a new substance being formed.
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What term describes a substance that is made up of two or more different elements?
What term describes a substance that is made up of two or more different elements?
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Which of the following describes a chemical change?
Which of the following describes a chemical change?
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Density depends on the size or mass of a substance.
Density depends on the size or mass of a substance.
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Define malleability in metals.
Define malleability in metals.
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In a chemical change, there is a change in the __________ composition.
In a chemical change, there is a change in the __________ composition.
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Match the following types of metals with their properties:
Match the following types of metals with their properties:
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Which property typically decreases from left to right across a period in the periodic table?
Which property typically decreases from left to right across a period in the periodic table?
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All elements in the periodic table are metals.
All elements in the periodic table are metals.
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What are the physical characteristics of metalloids?
What are the physical characteristics of metalloids?
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The formula for calculating density is __________ divided by volume.
The formula for calculating density is __________ divided by volume.
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Which of the following materials is likely to be a poor conductor of electricity?
Which of the following materials is likely to be a poor conductor of electricity?
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What distinguishes cations from anions?
What distinguishes cations from anions?
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Ions are formed only when there is an imbalance of neutrons in an atom.
Ions are formed only when there is an imbalance of neutrons in an atom.
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Who is most famously credited for the periodic table?
Who is most famously credited for the periodic table?
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The ____ principle states that electrons will occupy the orbitals with lower energy levels first.
The ____ principle states that electrons will occupy the orbitals with lower energy levels first.
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Match the following orbitals with their shapes:
Match the following orbitals with their shapes:
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Which element has the largest atomic radius?
Which element has the largest atomic radius?
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Ionization energy decreases down a group.
Ionization energy decreases down a group.
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What is electron affinity?
What is electron affinity?
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The atomic radius of ___ is the smallest.
The atomic radius of ___ is the smallest.
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Match the following terms with their definitions:
Match the following terms with their definitions:
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What generally happens to electronegativity as you move across a period?
What generally happens to electronegativity as you move across a period?
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Metallic character increases down a group.
Metallic character increases down a group.
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What trend is observed in nonmetallic characters across a period?
What trend is observed in nonmetallic characters across a period?
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As you go down a group, ionization energy generally ___ .
As you go down a group, ionization energy generally ___ .
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The tendency of an element to gain electrons is known as:
The tendency of an element to gain electrons is known as:
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What does the term 'atom' refer to?
What does the term 'atom' refer to?
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According to Niels Bohr's model, electrons orbit the nucleus at fixed distances.
According to Niels Bohr's model, electrons orbit the nucleus at fixed distances.
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Who proposed the Plum Pudding Model of atomic structure?
Who proposed the Plum Pudding Model of atomic structure?
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An atom's __________________ is determined by the number of protons it has.
An atom's __________________ is determined by the number of protons it has.
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Which of the following scientists is associated with the nuclear model of the atom?
Which of the following scientists is associated with the nuclear model of the atom?
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Electrons have more mass than protons in an atom.
Electrons have more mass than protons in an atom.
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What are isotopes?
What are isotopes?
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The first model of the atom, known as the __________ model, was proposed by John Dalton.
The first model of the atom, known as the __________ model, was proposed by John Dalton.
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Match the following scientists with their atomic models:
Match the following scientists with their atomic models:
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What significant property of electrons influences their arrangement around the nucleus?
What significant property of electrons influences their arrangement around the nucleus?
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Study Notes
Science 1st Semester Reviewer
-
Pointers:
- Particle Nature of Matter: elements, compounds, mixtures, atoms, molecules
- Atomic Structure: protons, neutrons, electrons (isotopes and ions)
- Periodic Table of Elements: development of atomic theory, arrangement of elements, reactive and non-reactive metals
- Quantum Mechanical Model (electron configuration)
Particle Nature of Matter
- Matter: Anything that has mass and occupies space.
- Kinetic Molecular Theory/Kinetic Particle Theory: Explains the nature of matter.
Explanation for the Particle Nature of Matter
-
Solids:
- Arrangement: regular array
- Distribution: packed closely together
- Attractive Forces: strong attractive forces
- Movement of Particles: vibrate, rotate, move in fixed positions only
-
Liquids:
- Arrangement: irregularly packed loosely
- Distribution: moderately strong attractive forces
- Attractive Forces: moderately strong attractive forces
- Movement of Particles: vibrate, rotate, and move freely (fluid) and randomly
-
Gases:
- Arrangement: no perceptible arrangement
- Distribution: farther apart from one another
- Attractive Forces: negligible attractive forces
- Movement of Particles: vibrate, rotate, move freely (fluid), randomly, rapidly, not constrained by other particles
Properties of Matter
-
Solids:
- Density: high
- Compressibility: non-compressible
- Shape/Volume: has a definite shape and volume
- Examples: salt, sugar
-
Liquids:
- Density: high
- Compressibility: slightly compressible
- Shape/Volume: takes the shape of the container and has a definite volume
- Examples: water, oil
-
Gases:
- Density: low
- Compressibility: highly compressible
- Shape/Volume: takes the shape and volume of its container
- Examples: helium, air
Physical Properties
- Determined without changing the substance's identity.
- Extensive: depends on the amount of substance (e.g., mass, volume).
- Intensive: does not depend on the amount of substance (e.g., density, color).
Chemical Properties
- Changes the identity of a substance.
- Describes how a substance reacts with air, acid, base, water, and other chemicals.
Particles of Matter
- Atom: basic unit of matter, smallest unit of an element.
- Elements: made up of identical atoms with the same mass, size, and properties.
- Molecules: combination of two or more atoms.
- Compounds: composed of atoms of more than one element.
Laws Governing the Particle Nature of Matter
-
Law of Chemical Combination:
- Law of Definite Proportions: the composition of a substance is the same regardless of the source or method of preparation.
- Law of Conservation of Mass: matter cannot be created or destroyed, only transformed.
- Law of Multiple Proportions: when two elements form more than one compound, the ratios of the masses of one element that combine with a fixed mass of the other element are in small, whole-number ratios.
Macroscopic Level
- Visible to the naked eye
Microscopic Level
- Requires an instrument to be seen (atoms,molecules)
Submicroscopic Level
- Only identifiable by behavior
Physical and Chemical Changes in Matter
-
Physical change:
- The material is structurally the same before and after change (examples include melting, shedding, boiling, chopping).
- Chemical change: A change in the chemical composition; often not reversible. (examples include combustion, rotting, rusting, digestion)
Density
- Mass per unit volume (mass/volume)
- Constant for a given substance
Reactive and Nonreactive Metals
- Metals: Most elements, naturally occurring, plentiful, good conductors, malleable.
- Nonmetals: Less common, poor conductors of electricity, brittle
Periodic Trends
- Atomic Radius: Size of an atom, generally decreases across a period and increases down a group.
- Ionic Radius: Size of a cation or anion, generally decreases across a period, and increases down a group.
- Ionization Energy: Energy to remove an outermost electron, generally increases across a period and decreases down a group.
- Electron Affinity: Energy change when an atom gains an electron, generally increases across a period and decreases down a group.
- Electronegativity: Tendency of an atom to attract shared electrons, generally increases across a period and decreases down a group.
History of Atoms
- 1803: John Dalton's solid sphere model (all matter composed of small particles)
- 1904: Thomson's plum pudding model (electrons scattered throughout positive sphere)
- 1911: Rutherford's nuclear model (atom has a dense positively charged nucleus, electrons outside).
- 1913: Bohr's planetary or modified nuclear model
- 1926: Schrodinger's quantum model (electrons behave like waves)
Atomic Structure
- Protons: positive charge
- Neutrons: no charge
- Electrons: negative charge
Isotopes and Ions
- Isotopes: Same atomic number, different atomic masses; differ in number of neutrons
- Ions: Atoms have an imbalance of protons and electrons; when an atom gains or loses electrons
Periodic Table of Elements
- Created through decades of experiments and discoveries by scientists.
Periodic Classification
- Columns (Groups): Similar elements; similar properties of elements.
- Rows (Periods): Correspond to the highest energy level.
- Elements in the same group have similar properties, while elements in the same period have different properties.
Quantum Mechanical Model
- States that electrons are in 3-dimensional regions around the nucleus.
- Atomic orbitals are different shapes.
- The orbitals fill up electron energy levels.
Electron Configuration
- Describes how electrons are distributed in an atom's energy levels.
- Describes the order and distribution of electrons in an atom's orbitals and subshells.
- Aufbau Principle: Electrons fill the lowest energy levels first.
- Pauli Exclusion Principle: A maximum of two electrons can occupy an orbital, with opposite spins.
- Hund's Rule: Electrons fill orbitals separately within a subshells before doubling up.
Questions
- Same electron configuration vs. same element?: Different electron configurations can mean different elements. The electron configuration shows the distribution of electrons among different orbitals within the atom.
- Why is "s" first when distributing electrons?: S orbitals have lower energy levels, and the energy configuration is distributed accordingly.
- Why are d and f orbitals not in the first energy level?: Their high energy levels prevent them from occupying energy level one, thus they are filled in later.
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Description
Test your understanding of the fundamental concepts of matter and its properties. This quiz covers topics such as the units of matter, chemical and physical changes, and the periodic table. Perfect for students studying chemistry fundamentals!
