- Chemistry
- 9 Grade ANN Mwandiki
YEAR 9 CHEMISTRY END OF SEMESTER 1 EXAMS 1. Complete the table by deciding if the information indicates that the element is a metal or a non-metal. (5) 2. Look at the table. It shows the melting points and boiling points of some elements. Use the table to answer these questions. (a) Write down the name of the element that melts at 1538°C. (1) (b) Which element is a liquid at room temperature (20°C)? (1) (c) Which element is a non-metal? (1) 3. Hydrogen peroxide is used to make oxygen in the laboratory. Hydrogen peroxide breaks down to form water and oxygen. (a) This reaction is much faster when a chemical called manganese(IV) oxide is added to the hydrogen peroxide. The manganese(IV) oxide is unchanged at the end of the reaction. What type of chemical is manganese(IV) oxide?
Tick (√) the correct answer.(1) (b) Blessy investigates the effect of temperature on the breakdown of hydrogen peroxide. (i) Write down the variable she should change. (2) (ii) Write down one variable she should control (keep the same). (2) 4. Complete the word equations 5.(a) Draw the electronic structure of an atom of aluminium. The atomic number of aluminium is 13. (3) (b) Write the electronic configuration of aluminium. (1) 6. Ernest Rutherford helped to develop a model of the atom.(4) (a) Label the diagram of a helium atom using these words.
Electron nucleus neutron proton (b) Ernest Rutherford fired very small particles at a thin gold foil. The diagram shows the path of the particles. Most of the particles pass straight through the gold foil. Other particles are scattered when they hit part of the gold atom. What part of the gold atom causes the small particles to scatter? (1) 7. Chemicals can be elements or compounds. Tick (√) the box to show which chemicals are elements and which chemicals are compounds. The first one has been done for you.(4)
8.a) What is the name of the element that has electron arranged 2,8,2 (1) b)Draw the electron structure of the element you named in (a) above. (3) 9. Where in the periodic table do you find metals? (1) 10.What happens to the size of atoms as you move done the group? (2) 11. a) Define halogens. (2) b) Suggest why the above group is called group 7. (2) 12.List two noble gases. (2)
13.a) What an exothermic reaction. (2) b) Give an example. (1) 14. Write a use of endothermic reactions. (1) 15. The following equations show four reactions.(3) Give the letter A,B,C or D of the reaction that is i. a neutralization reaction ii. a displacement reaction iii. a reaction in which a metal oxide is formed. 16.Write a word equation for the reaction between aluminium and iron oxide. (1)