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Mastering Biology2
Chapter 2
Question | Answer |
---|---|
In the term trace element, the adjective trace means that | the element is required in very small amounts. |
Compared with 31^P, the radioactive isotope 32^P has | one more neutron |
The reactivity of an atom arises from | the existence of unpaired electrons in the valence shell |
We can represent atoms by listing the number of protons, neutrons, and electrons-for example, 2p+, 2n0, 2e- for helium. What represents the 18^O isotope of oxygen? | 8p+, 10n0, 8e- |
The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound. | H_2S |
Which statement is true of all atoms that are anions? | The atom has more electrons than protons |