General Chemistry Name :
Worksheet : Chs. 7 ; Obj. 1-11 Date :
A. Read pp. 194 - 207 and answer the following questions :
1. ______are the electrons in the highest occupied energy level of an element's atoms.
2. Circle the valence electrons in the following electron configuration of magnesium.
1s2 2s2 2p6 3s2
3. _____ (T/F) The number of valence electrons is very important in determining the chemical properties of an element.
4. _____ (T/F) The elements of a group have different numbers of valence electrons.
5. _____ (T/F) The representative groups 1A-7A have the same number of valence electrons as their group number.
6. State the number of valence electrons of the following elements :
_____ oxygen _____ argon _____ fluorine
_____ helium _____ lithium _____ krypton
_____ magnesium _____ neon _____ potassium
7. _____ (T/F) Valence electrons are usually the only electrons involved in a chemical bond.
8. _____ (T/F) Electron dot structures show the valence electrons as dots around the symbol of the element.
9. Show the electron dot structures of the following elements :
Calcium Ca chlorine Cl
Rubidium(Rb - 37) Rb tin (Sn - 50) Sn
10. _____ (T/F) The higher the energy level, the more stable an atom or ion is.
11. _____ (T/F) Stable electron configurations have a low level of energy.
12. State the octet rule and who proposed the octet rule and when.
13. Neon has the following electron configuration : 1s2 2s2 2p6 . Answer the following questions true or false based on this electron configuration.
_____ Neon has a very stable electron configuration.
_____ Neon has a low level of energy.
_____ Magnesium (1s2 2s2 2p6 3s2) needs to lose two electrons to become as stable as neon.
_____ Magnesium will have a negative two (2-) charge after it loses two electrons.
_____ Fluorine will need to gain one electron to get the electron configuration of neon and will have an ionic charge of 1-.
14. _____ (T/F) Calcium will need to lose two electrons to get the electron configuration of argon.
15. _____ (T/F) All the alkaline earth elements (Group 2A) will need to lose two electrons to obtain a noble gas electron configuration.
16. _____ (T/F) All the elements of the oxygen group (Group 6A) will need to gain two electrons to obtain the electron configuration of a noble gas.
17. _____ (T/F) All the elements of Group 6A are likely to have a 2- ionic charge.
18. _____ (T/F) All the elements of group 3A (aluminum group) will probably gain 5 electrons to get a noble gas electron configuration.
19. ______are charged atoms or groups of atoms.
20. ______are positively charged ions.
21. ______are negatively charged ions.
22. _____ (T/F) Anions are formed by the loss of electrons.
23. _____ (T/F) Cations are formed by the gain of protons.
24. ______ions are the ions of the halogens and have a 1- charge,
25. ______compounds are composed of positive and negative ions.
26. _____ (T/F) A formula unit shows the smallest whole-number ratio of ions in a molecular compound.
27. _____ (T/F) Ionic compounds are composed of nonmetallic elements.