1. Atoms and Reactions Test 1a Biology

2. 1) ____________is anything that occupies space and has mass. Matter

3. 2) _______________ are particles in an atom that are positively charged, composed of two Up Quarks and one Down Quark, and have a mass = 1 amu. Protons 3) What does “amu” stand for? _______________. atomic mass units

4. 4)Electrons are located in, and rapidly travel through, the ______________ around the nucleus (in energy levels), created by the movement of the electrons. electron cloud

5. 5) The smallest combined unit of atoms with covalent bonds is called a _______________. molecule

6. 6) The number of _____________ in the nucleus of an atom is what determines what element it belongs to. Protons

7. 7) The total number of protons and neutrons in an atom is called its _____________. Atomic Mass.

8. 8) ________________ are particles in an atom that is negatively charged, a fundamental particle, and have a mass = 0.000548579909 amu. Electrons

9. 9) _____________ is when the nucleus of atom throws out particles (either alpha or beta) because the atom decays. Radioactivity

10. 10) ____________ are particles in an atom that has no charge, composed of one Up Quark and two Down Quarks, and have a mass = 1 amu. Neutrons

11. 11) An atom’s Atomic Number is determined by the number of _______________ it has. Protons

12. 12) The number of electrons in the outermost electron shell of an atom are called _______________ electrons and determines the chemical properties of that atom. valence

13. 13-16) What are the four elements that make up 96% of most living organisms. ____________________ ____________________ C, H, O, N

14. 17) Many molecules (only covalently bonded) have the protons within the molecule scattered unevenly around the molecule’s shape. This unevenness of the positive charges in the molecule causes the electrons to be shared unevenly also, with the electrons spending more of their time around the greater number of protons and less around the other areas of the molecule. This unevenness of the sharing of electrons and their negative charge creates molecules with poles – slightly positive and slightly negative, hence are called ________________ molecules. Polar

15. 18) Elements can combine chemically to form ______________. compounds

16. 19) Chemical bonds can hold atoms together in two different ways: _____________ bonds and _____________ bonds Ionic, Covalent

17. 20) When an atom loses or gains electrons, it becomes electrically charged and becomes an _____________. ion

18. 21) _______________ bonding occurs when pairs of electrons are shared by atoms. Covalent

19. 22) Atoms have Protons (and Neutrons) in the area of the atom called the _____________. nucleus

20. 23) If a hydrogen atom is at the positive end of a polar bond, it is called a ______________ bond. hydrogen

21. 24) A ______________ is a liquid consisting of two or more substances evenly mixed. solution 25) The dissolving agent (the larger amount of substance) is called the _______________. solvent 26) The dissolved substance (the smaller amount of substance) is called the _______________. solute

22. 27) The smallest unit of matter (that retains the properties of an element) is called an _______________. Atom

23. 28) A chemical compound that donates H+ ions to the solution (creating an excess of H+ ions in the final solution) is called a(n) ____________. acid 29) A compound that accepts H+ ions and removes them from solution (creating excess OH- ions in the final solution) is called a(n) ______________. base

24. acid atom atomic mass atomic mass units base carbon compounds covalent electron cloud electrons hydrogen ion ionic matter molecule neutrons nitrogen nucleus oxygen phosphorus polar potassium protons radioactivity sodium solute solution solvent valence

25. 30-36) Use the models above to make a Cl (chlorine) atom and a Na (sodium) atom. Atomic number of Chlorine = 17 Atomic number of sodium = 11 -6

26. 37-43) Use the models above to make a chlorine ion (Cl-) and a sodium ion (Na+). Atomic number of Chlorine = 17 Atomic number of sodium = 11 -6

27. 44-49) Use the models above to make the following two isotopes of Chlorine (Cl) Cl – 18 Chlorine – 19 -6

28. 50-58) Use the model below to make a water molecule – H 2 0 Atomic number of Oxygen = 8 Atomic number of Hydrogen = 1 -9