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6 Cards in this Set
- Front
- Back
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How many chemical elements of the body are there? What are the main six, and the lesser six? |
There are 24 chemical elements of the body. The main six make up 98.5% of the body's weight. They are oxygen (O), carbon (C), hydrogen (H), nitrogen (N), calcium (Ca), phosphorus (P). The other 0.8% are sulfur (S), potassium (K), sodium (Na), chlorine (Cl), magnesium (Mg), iron (Fe). |
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How are protons, neutrons, and electrons are organized into atoms? |
Electrons surround the nucleus in electron shells The more energy an electron has, the farther away from the nucleus its orbit lies. The protons and neutrons make up the nucleus, the center of the atom. |
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Distinguish between ions, electrolytes, and free radicals. |
Ions are charged particles with unequal numbers of protons and electrons. Electrolytes are substances that ionize in water (acids, bases, or salts) and form solutions capable conducting electricity. Free Radicals are chemical particles with an odd number of electrons. |
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Define the types of chemical bonds. |
- Ionic bond: relatively weak attraction between an anion and a cation. Easily disrupted in water, as when salt dissolves. - Covalent bond: Sharing of one or more pairs of electrons between nuclei - Hydrogen bond: Weak attraction between polarized molecules or between polarized regions of the same molecule. Important in the three-dimensional folding and coiling of large molecules. Easily disrupted by temperature and pH changes. |
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Explain how electrons are organized into energy levels, or "shells" around the nucleus of an atom, and how many electrons are necessary to fill each of the lowest three energy levels. |
The electron shells surround the nucleus of an atom. The more energy an electron has the farther away from the nucleus its orbit lies. Each shell holds a limited number of electrons. The first energy level holds 2 electrons, the further ones hold 8 electrons. |
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Explain how both single and double covalent bonds form. |
Single covalent bond is the sharing of a single pair of electrons. Double covalent bond is the sharing of two pairs of electrons. |
