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66 Cards in this Set
- Front
- Back
All matter is composed of _____. |
Atoms. |
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Understanding the structure of atoms is critical to understanding the natural of ________ ________. |
Biological molecules. |
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Atoms are composed of: |
Protons, neutrons, and electrons. |
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Positively charged particles. |
Protons. |
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Neutral particles. |
Neutrons. |
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Negatively charged particles. |
Electrons. |
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Protons and neutrons are located in the _______. |
Nucleus. |
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Electrons are found in: |
Orbitals surrounding the nucleus. |
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What is atomic number? |
The number of protons |
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Every different atom has a characteristic number of protons in the: |
Nucleus. |
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Atoms with the same atomic number have the same chemical properties and belong to the same ______. |
Element. |
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Each proton and neutron has a max of approximately __ _________. |
1 dalton. |
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The sum of protons and neutrons is the atom’s _________ _______. |
Atomic mass. |
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Atoms of the same element that have different atomic mass numbers due to different numbers of neutrons: |
Isotopes. |
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6 protons, 6 neutrons, 6 electrons. |
Carbon-12 |
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6 protons, 7 neutrons, 6 electrons |
Carbon-13 |
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6 protons, 8 neutrons, 6 electrons |
Carbon-14 |
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_______ atoms have the same number of protons and electrons. |
Neutral. |
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____ are charged atoms. |
Ions. |
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______ have more protons than electrons and are positively charged. |
Cations |
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______ have more electrons than protons and are negatively charged. |
Anions |
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Electrons are located in ______ surrounding the nucleus. |
Orbitals. |
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Each orbital can only contain ____ electrons. |
2 |
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Electrons possess potential energy, with electrons far from the nucleus having the ______ energy. |
Most |
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Loss of an electron is: |
Oxidation |
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Gain of an electron is: |
Reduction. |
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The electrons in the outermost energy level of an atom are the : |
Valence electrons. |
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An element’s chemical properties depend on interactions between : |
Valence electrons of different atoms. |
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The _______ _______ arranges all elements according to their atomic number. |
Periodic table. |
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Atoms tend to establish completely-full outer energy levels. |
Octet rule. |
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Atoms with ____ energy levels are less reactive than atoms with ________ energy levels. |
Full, unfilled |
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There are __ naturally occurring elements. |
90 |
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Only __ elements are found in living organisms in substantial amounts. |
12 |
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Four elements make up 96.3% of human body weight: |
Carbon, hydrogen, oxygen, nitrogen. |
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______ are groups of atoms held together in a stable association. |
Molecules |
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______ are molecules containing more than one type of element. |
Compounds. |
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Atoms are held together in molecules or compounds by _______ ______. |
Chemical bonds |
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______ bonds are formed by attraction of oppositely charged ions. |
Ionic |
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________ bonds form when atoms share 2 or more valence electrons. |
Covalent |
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Covalent bond strength depends on the number of _____ pairs shared by the atoms. |
Electron. Single bond < double bond < triple bond |
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_______________ is an atom’s affinity for electrons. |
Electronegativity. |
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Equal sharing of electrons |
Nonpolar covalent bonds. |
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Unequal sharing of electrons |
Polar covalent bonds. |
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Chemical reactions involve the formation or: |
Breaking of chemical bonds |
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Whether a chemical reaction occurs is influenced by: |
Temperature, concentration of reactants and products, and availability of a catalyst. |
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Chemical reactions are written with the: |
Reactants first, followed by the products. |
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All living organisms are dependent on: |
Water. |
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The most important property of water is the ability to form: |
Hydrogen bonds |
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Within a water molecule, the bonds between oxygen and hydrogen are : |
Highly polar. |
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Partial electrical charges develop within a water molecule: |
Oxygen is partially negative, hydrogen is partially positive. |
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These can form between water molecules or between water and another charged molecule. |
Hydrogen bonds. |
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The polarity of water causes it to be : |
cohesive and adhesive. |
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Water molecules stick to other water molecules by hydrogen bonding. |
Cohesion. |
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Water molecules stick to other polar molecules by hydrogen bonding. |
Adhesion. |
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Water has a high specific heat. |
A large amount of energy is required to change the temperature of water. |
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Water has a high heat of vaporization. |
The evaporation of water from a surface causes cooling of that surface. |
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Solid water is less dense than liquid water. |
Bodies of water freeze from the top down. |
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Water is a good solvent. |
Water dissolved polar molecules and ions. |
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Water-loving |
Hydrophilic |
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Water-fearing |
Hydrophobic |
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Hydrogen ion (H+1) is the basis of the __ ____. |
pH scale. |
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Greater H+1 concentration = |
Lower pH (acidic) |
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A chemical that releases H+1 ions. |
Acid. |
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A chemical that accepts H+1 ions. |
Base. |
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A chemical that accepts/releases H+1 as necessary to keep pH constant. |
Buffer. |
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Most biological buffers consist of a pair of molecules, one an ______ and one a _____. |
Acid and a base. |