Higher Chemistry
Unit 1 Chemical Changes and Structure-Bonding in ELEMENTS homework
1. Which of the following elements is monatomic at room temperature and pressure?
A. Argon
B. Chlorine
C. Hydrogen
D. Nitrogen
2. Which of the following elements consists of discrete covalent molecules?
A. Lithium
B. Carbon
C. Hydrogen
D. Silicon
3. Which of the following molecules consists of polyatomic X4 molecules?
A. Nitrogen
B. Sulfur
C. Magnesium
D. Phosphorus
4. The elements lithium, boron and nitrogen are in the second period of the
Periodic Table.
Complete the table below to show both the bonding and structure of these three
elements at room temperature
5. Diamond and graphite are forms of carbon that exist as network solids.
Name a form of carbon that exists as discrete molecules.
6 (a) Complete the table below by adding the name of an element from elements 1 to 20
of the Periodic Table for each of the types of bonding and structure described.
(b) Why do metallic solids such as potassium and sodium conduct electricity?
7. The diagram shows the melting points of successive elements across a period in the
Periodic Table.
Which of the following is a correct reason for the low melting point of element Y?
A. It has weak ionic bonds
B. It has weak covalent bonds
C. It has weakly-held outer electrons
D. It has weak forces between molecules
8. Which type of bonding is never found in elements?
A. Metallic
B. Van der Waals’
C. Polar covalent
D. Non-polar covalent
9. Which of the following elements exists as discrete molecules?
A. Boron
B. Carbon (diamond)
C. Silicon
D. Sulfur
10. Which of the following does not contain covalent bonds?
A. Hydrogen gas
B. Helium gas
C. Nitrogen gas
D. Solid sulfur
11. Element X was found to have the following properties.
It does not conduct electricity when solid.
It forms a gaseous oxide.
It is a solid at room temperature.
Element X could be
A. magnesium
B. silicon
C. nitrogen
D. sulfur
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12. A metal (melting point 328 C, density 11∙3 g cm-3) was obtained by electrolysis of
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its molten chloride (melting point 501 C, density 5∙84 gcm-3).
During the electrolysis, how would you observe the metal?
A. As a solid on the surface of the electrolyte
B. As a liquid on the surface of the electrolyte
C. As a solid at the bottom of the electrolyte
D. As a liquid at the bottom of the electrolyte
13. What are the forces of attraction holding helium atoms together called?
A. Hydrogen bonds
B. London dispersion forces
C. Covalent bonds
D. Metallic bonds
14. Which of the following statements explains why diamond has such high melting
and boiling points?
A. Diamond molecules are held together by strong London dispersion forces.
B. The metallic bonds in diamond are very strong.
C. The carbon atoms in diamond are held together by strong covalent bonds.
D. The carbon atoms in diamond are held together by strong hydrogen bonds.
E. The carbon atoms have strong triple covalent bonds holding them together.
15. The layers of carbon atoms in graphite are held together by
A. metallic bonds
B. covalent bonds
C. hydrogen bonds
D. London dispersion force