1. Physics and Chemistry 3rd ESO Albarregas High School
CHEMICAL BOND
Activities
Activity 1: According to their place in the periodic table, which of these elements tend to
form cations? Which of them tend to form anions? Fill in the table.
Name Symbol Group Valence Cation or Charge
electrons anion
Chloride
Se
Potassium
Al
Calcium
Nitrogen
Activity 2: Aluminium and nitrogen form an ionic compound called aluminium nitride.
a) How many valence electrons does each element have?
b) Answer these questions for an aluminium atom.
b.1) Does it gain or lose electrons to form the ion?
b.2) How many electrons are transferred?
b.3) Is the ion formed positive, or negative?
b.4) What charge does the ion have?
c) Repeat the questions b) for a nitrogen atom.
d) Write the formula of aluminium nitride.
d) Give the electron arrangement for both ions. What do they have in common?
Activity 3: Write Lewis structures of the ionic compounds formed by:
a) K and Br
b) Mg and Se
c) K and S
d) Ca and F
Activity 4: Explain why the formula of sodium chloride is NaCl and the formula of calcium
chloride is CaCl2.
Activity 5: Explain why helium is made of atoms but other gasses like chloride, hydrogen,
oxygen or nitrogen are made of molecules. Explain how the bond is in those molecules.
Activity 6: Both, oxygen and diamond have the same kind of bond, but they have really
different properties. Look for their properties in the Internet and explain why they are so different.
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2. Physics and Chemistry 3rd ESO Albarregas High School
Activity 7: For these elements: N, C, O and F:
a) Write the number of valence electrons.
b) Write the structure and the formula of:
b.1) the compounds that each of them form with hydrogen.
b.2) the compound formed by F and O
b.3) the compound formed by N and F
Activity 8: Match:
Gold Molecular compound Cations and electrons
water Ionic lattice molecules
quartz Metallic lattice Anions and cations
salt Covalent lattice atoms
Activity 9: Neither salt nor water can conduct electricity but a mixture of them can. Explain
why.
Activity 10: A piece of magnesium contains 300 billions atom. How many electrons are in
its electron cloud?
Activity 11: Which of these substances have covalent bond and which of them has ionic
bond? KCl, CO2, CCl4, NaI, KBr, Na2S, Br2, SiO2
Activity 12: Sodium and sodium chloride have very similar structure, but one of them can
conduct electricity and the other can't. Explain why.
Activity 13: Only one of them is the correct formula of calcium sulfide: CaS 2; Ca2S; CaS,
Ca3S. Taking into account the number of valence electrons of calcium and sulfur, explain which one
is the correct formula.
Activity 14: Carbon and oxygen form a covalent named carbon dioxide whose formula is
CO2
a) How many valence electron does a isolated carbon atom have? What about oxygen?
b) In a carbon atom, how many pairs of electrons does carbon need to share in order to get a
stable electron arrangement? What about oxygen?
c) Apart form that, is there another way so that an oxygen atom gets a stable electron
arrangement? Explain it and give an example.
d) Write the structure of carbon dioxide.
Activity 15: All alkali metals react with oxygen and form compounds with very similar
formulae: Li2O; Na2O; K2O; Rb2O;... Is this a coincidence or is there a reason for this? Explain it.
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3. Physics and Chemistry 3rd ESO Albarregas High School
Activity 16: In the following table there are the properties of several substances. According
to that information, answer the questions.
a) Which of the substances are metals?
b) Which of the substances are ionic compounds?
c) There are two substances with very low melting points. What kind of substances are they?
d) Which substance is a covalent crystal?
Substance Melting point (ºC) Electrical conductor in Electrical conductor Soluble in
solid state? in liquid state? water?
A -112 ºC No No No
B 680 ºC No Yes Yes
C -70 No No No
D 1495 Yes Yes No
E 610 No Yes Yes
F 1610 No No No
G 660 Yes Yes No
Activity 17: Complete the crossword with English words and translate them into Spanish.
ACROSS Translations
1. Elements that tend to gain electrons.
4. Kind of chemical bond in which one or several pairs of electrons are shared.
6. Chemical _____________ is how atoms get together.
8. Most noble gasses have _________ valence electrons.
9. Hard material is difficult to ______________
11. __________ shell is the last one of an atom.
13. Metals consist of anions and a _________ of electrons
14. A ___________ is formed by a few atoms connected by covalent bonds.
16. Expresses the elements that form a compound and their proportion.
17. Tendency of many elements to get eight valence electrons.
18. kind of chemical bond in iron
DOWN Translations
1. ________ gasses are elements that don't bond to others.
2. __________ structure shows the bonds in a molecule
3. Kind of chemical bond between a metal atom and a nonmetal one
5. Ordered pattern of particles in a crystal
7. Positive ion
10. Elements that tend to lose electrons
12. Negative ion
15. Material whose particles are arranged in an ordered pattern.
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4. Physics and Chemistry 3rd ESO Albarregas High School
You must also do the following activities from yor P&C book:
On page 74: 3 and 4
On page 76: 9
On page 77: 11
On page 85: 36 and 38
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