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Questions and Answers
In a polar covalent bond, atoms share electrons unequally.
In a polar covalent bond, atoms share electrons unequally.
True
Buffers compensate for pH changes by releasing or absorbing H+ ions.
Buffers compensate for pH changes by releasing or absorbing H+ ions.
True
The exclusion of polar substances from the interior of a lipid bilayer is essential for cells to survive.
The exclusion of polar substances from the interior of a lipid bilayer is essential for cells to survive.
True
Water has a very large specific heat, which helps prevent temperature changes in large bodies of water, such as Lake Michigan or any ocean.
Water has a very large specific heat, which helps prevent temperature changes in large bodies of water, such as Lake Michigan or any ocean.
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A covalent bond is formed when atoms gain or lose electrons.
A covalent bond is formed when atoms gain or lose electrons.
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An atom that has its outer energy level completely filled with electrons is highly reactive.
An atom that has its outer energy level completely filled with electrons is highly reactive.
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Molecular geometries dictate the function of a molecule.
Molecular geometries dictate the function of a molecule.
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Nitrogen is one of the four elements that make up 96% of the weight of living organisms.
Nitrogen is one of the four elements that make up 96% of the weight of living organisms.
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An atom is the smallest unit that retains the chemical and physical properties of an element.
An atom is the smallest unit that retains the chemical and physical properties of an element.
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The formation of an extensive network of van der Waals forces between water molecules is the reason that the solid form of water floats, unlike most substances that transition from a liquid to a solid state.
The formation of an extensive network of van der Waals forces between water molecules is the reason that the solid form of water floats, unlike most substances that transition from a liquid to a solid state.
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The tendency of water molecules to stick to the walls of root tubes, known as _____, aids in moving water from roots up to the tops of plants.
The tendency of water molecules to stick to the walls of root tubes, known as _____, aids in moving water from roots up to the tops of plants.
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Which property of water allows humans to cool off by sweating?
Which property of water allows humans to cool off by sweating?
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A substance that cannot be broken down by ordinary chemical or physical means is a(n) ____.
A substance that cannot be broken down by ordinary chemical or physical means is a(n) ____.
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The region of space where an electron 'lives' most of the time is called a(n) ____.
The region of space where an electron 'lives' most of the time is called a(n) ____.
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A solution with a pH of 10 is ____.
A solution with a pH of 10 is ____.
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Which element is a trace element?
Which element is a trace element?
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When an ionic compound such as table salt (NaCl) is dissolved in water, ____.
When an ionic compound such as table salt (NaCl) is dissolved in water, ____.
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The bonds in iodine gas (I2) are _____ bonds, while the bonds in SH2 are _____.
The bonds in iodine gas (I2) are _____ bonds, while the bonds in SH2 are _____.
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In an acidic solution, ____.
In an acidic solution, ____.
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Bonds that are the result of electrical attractions between atoms that gain or lose valence electrons are called ____ bonds.
Bonds that are the result of electrical attractions between atoms that gain or lose valence electrons are called ____ bonds.
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How many key elements are living things composed of?
How many key elements are living things composed of?
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An ______ is the simplest substance.
An ______ is the simplest substance.
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___________ make up 96% of the weight of living organisms.
___________ make up 96% of the weight of living organisms.
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The other 4 elements are Ca, P, K, Na, Cl, Mg, S which make up ____.
The other 4 elements are Ca, P, K, Na, Cl, Mg, S which make up ____.
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Trace elements are essential for various biochemical reactions.
Trace elements are essential for various biochemical reactions.
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Study Notes
Fundamental Concepts of Chemical Bonds and Properties of Water
- Polar Covalent Bonds: Electrons are shared unequally between atoms, leading to partial charges.
- Buffers: Compensate for pH changes by releasing or absorbing hydrogen ions (H+).
- Lipid Bilayers: The exclusion of polar substances is crucial for cell survival, maintaining a hydrophobic environment.
- Water's Specific Heat: High specific heat capacity stabilizes temperatures in large water bodies, important for climate regulation.
Misconceptions About Chemical Properties
- Covalent Bonds: Formed by the sharing of electrons, not gaining or losing them.
- Reactivity of Atoms: Atoms with full outer energy levels are typically not reactive (noble gases).
Molecular and Atomic Characteristics
- Molecular Geometries: Shape of a molecule is critical as it influences biological functions and interactions.
- Key Elements in Organisms: Nitrogen is one of the four elements (CHON) that constitute 96% of living organism’s mass.
- Atoms: Defined as the smallest unit retaining an element's chemical and physical properties.
Properties of Water
- Adhesion: Water molecules sticking to the walls of root tubes assists in water transport within plants.
- Heat of Vaporization: This property allows for effective cooling through sweating in humans.
- Solid Water: Ice floats due to lower density resulting from hydrogen bonding, not van der Waals forces.
Solutions and pH
- Basic Solutions: Solutions with a pH above 7, such as pH 10, are considered basic.
- Acidity: In acidic solutions, there is a greater concentration of H+ ions compared to hydroxide ions (OH-).
Ionic Compounds
- Dissolving in Water: Ionic compounds like sodium chloride (NaCl) dissociate due to the water lattice's polarity, separating Na+ from Cl- ions.
- Ionic Bonds: Formed from the electrical attractions between atoms that gain or lose valence electrons.
Elements and Compounds
- Trace Elements: Essential in small amounts, iodine is an example of a trace element.
- Living Organisms Composition: Composed mainly of 25 key elements, with a significant portion being CHON (carbon, hydrogen, oxygen, nitrogen).
- Other Important Elements: Calcium (Ca), phosphorus (P), potassium (K), sodium (Na), chlorine (Cl), magnesium (Mg), and sulfur (S) constitute about 4% of living matter.
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Description
Test your understanding of key concepts in biology with these flashcards related to polar covalent bonds, buffers, lipid bilayers, and water's specific heat. Each card provides a definition to enhance your learning. Ideal for students prepping for exams or revising important topics.
