Amplifiers Which of the following subatomic particles has appreciable mass and lacks a charge? a. NEUTRON 2. The fact that oxygen is an atom that is strongly electronegative means that __________. a. IT MORE STRONGLY PULLS SHARED ELECTRONS TOWARD ITSELF WHEN FORMING A COVALENT BOND WITH A LESS ELECTRONEGATIVE ATOM 3. Weak chemical bonds such as hydrogen bonds __________. a. FORM WHEN A HYDROGEN ATOM THAT IS COVALENTLY BONDED TO AN ELECTRONEGATIVE ATOM LIKE OXYGEN OR NITROGEN IS ATTRACTED TO ANOTHER ELECTRONEGATIVE ATOM 4. Molecular mimics __________. a. CAN PRODUCE SIMILAR EFFECTS AS THE NATURALLY OCCURRING MOLECULES 5. Isotopes of an element will always differ in __________. a. ATOMIC MASS 6. The number of protons in an uncharged atom __________. a. EQUALS THE NUMBER OF ELECTRONS 7. The molecular shape of a biological molecule is important because __________. a. IT DETERMINES HOW BIOLOGICAL MOLECULES RECOGNIZE AND RESPOND TO ONE ANOTHER 8. Ionic bonds form as a result of __________. a. ATTRACTION BETWEEN IONS THAT HAVE OPPOSITE CHARGES 9. A covalent bond __________. a. IS THE SHARING OF A PAIR OF VALENCE ELECTRONS BY TWO ATOMS 10. The chemical characteristics or reactivity of an element depend mostly on the __________. a. NUMBER OF ELECTRONS IN ITS OUTERMOST SHELL 11. Trace elements __________. a. ARE REQUIRED BY AN ORGANISM IN MINUTE QUANTITIES 12. Nonpolar covalent bonds are always formed from atoms that are __________. 1. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. a. EQUAL IN THEIR ELECTRONEGATIVITY Which of the following has negligible mass? a. ELECTRON When the proton number and electron number are unequal, the atom or molecule __________. a. IS AN ION Hydrogen bonds occur when __________. a. PARTIAL OPPOSITE CHARGES ON MOLECULES COME CLOSE ENOUGH TO ATTRACT EACH OTHER Which statement is true of all atoms that are anions? a. THE ATOM HAS MORE ELECTRONS THAN PROTONS A covalent bond is likely to be polar if __________. a. ONE OF THE ATOMS SHARING ELECTRONS IS MUCH MORE ELECTRONEGATIVE When one or more pairs of valence electrons are shared by two neutral atoms, what type of bond is formed? a. A COVALENT BOND What are the four most abundant elements found in living systems? a. HYDROGEN, OXYGEN, NITROGEN, AND CARBON Radioactive tracers _________. a. ARE IMPORTANT TOOLS IN BIOLOGICAL RESEARCH AND MEDICINE In a process called radiometric dating, scientists measure the __________ of an isotope to determine the age of the Earth. a. HALF-LIFE The difference between a stable isotope and an unstable isotope of an element is that __________. a. THE UNSTABLE ISOTOPE HAS A NUCLEUS THAT DECAYS SPONTANEOUSLY, IS RADIOACTIVE, AND CAN BE TRANSFROMED INTO AN ATOM OF ANOTHER ELEMENT The reactivity of an atom arises from __________. a. THE EXISTENCE OF UNPAIRED ELECTRONS IN THE VALENCE SHELL In chemical reactions, the __________ are the starting materials that are converted into the __________. a. REACTANTS; PRODUCTS Which of the following statements is true about chemical reactions? a. THEY INVOLVE THE MAKING AND BREAKING OF CHEMICAL BONDS The behavior of an atom depends on the __________. a. VALENCE ELECTRONS IN THE OUTERMOST ELECTRON SHELL 27. In ionic interactions, __________. a. THE TRANSFER OF VALENCE ELECTRONS RESULTS IN A COMPLETED VALENCE SHELL FOR EACH ION 28. When a very electronegative atom strips a valence electron away from its partner, __________ form. a. IONS 26.