-
In the figure below, the tangent ST meets chord VU produced at T. Chord SW passes through the centre O, of the circle and intersects chord VU at X. Line ST = 12cm and UT = 8cm.
a)Calculate the length of chord VU.
b)If WX = 3cm and VX : XU = 2 : 3, find SX.
Date posted:
October 16, 2019
-
Use the scheme to answer the questions that follow:
(a) Identify solid N
(b) Write a balanced equation for the formation of Q
(c) Write the formula of the complex ion formed when sodium hydroxide is added to solution L in excess
Date posted:
October 16, 2019
-
(i) By parametric formula with reference to a standard table using a graphical method. [4]
(ii) Outline the steps involved in graduating mortality rates with reference to a
standard table [3]
Date posted:
October 15, 2019
-
Name the type of bonding and structure found in: -
(a) Ice
(b) Magnesium chloride
Date posted:
October 15, 2019
-
The atomic number of element P is 11 and that of Q is 8
a) Write down the possible formula of the compound formed between P and Q
b) Using dots (·) and crosses(x) to represent electrons draw a diagram to represent the bonding in the compound in (a) above
Date posted:
October 15, 2019
-
The table below shows the elements in the third period, the oxides of the third period and their properties. The letters are not the actual symbols of the elements. Study the information and answer
the questions that follow:
i) Complete the table above
ii) Explain the trend in the atomic radius across the period
iii) Explain why the oxide of element V does not exist
Date posted:
October 15, 2019
-
The grid below represents part of the periodic table. The letters do not represent actual symbols of the elements. Study it and answer the questions that follow:-
(a) What type of bond would you expect in the compound formed between H and F. Explain
(b) (i) Which of the elements J and M will have a greater atomic radius? Explain
(ii) Elements F and N are in the same group of periodic table. How do their atomic
radius compare? Explain
(c) An element W has atomic number 15. Indicate the position it would occupy in the table above
(d) What is the name given to elements X – Z?
(e) Why is J used in electric cables where Q is not
(f) P and J are termed as metalloids. What does the term metalloid mean?
(g) How would you expect the reactivity of H and M to compare? Explain
Date posted:
October 15, 2019
-
Sodium metal tarnishes when exposed to the air where a white powder is formed on its
surface. A small piece of this sodium metal was dropped into 25g of ethanol and 1200cm3
of hydrogen gas was evolved at r.t.p. The unreacted ethanol was evaporated and a white
solid remained. (Na=23, molar gas volume at r.t.p = 24dm3, C=12, O =16, H=1)
(a) Write a chemical equation for the reaction between ethanol and sodium metal
(b) Determine the mass of sodium that reacted with ethanol
(c) What mass of ethanol evaporated?
(d) The ethanol was evaporated at 80oC, while the white solid remained unaffected at this
temperature. What is the difference in structure of ethanol and the white solid?
(II) (a) Name an inorganic liquid which liberates hydrogen gas with sodium metal
(b) What two differences would you observe if similar pieces of sodium were dropped
separately into small beakers containing equal amount of ethanol and the liquid
named in (II)(a) above respectively
Date posted:
October 15, 2019
-
Explain the following observations:-
(i) NaCl allows electric current to pass through them in molten state
(ii) Graphite is a non-metal yet it is a conductor of electricity
Date posted:
October 15, 2019
-
Explain how electrical conductivity can be used to distinguish between magnesium oxide and silicon (IV) oxide
Date posted:
October 15, 2019
-
Explain why luminous flame is capable of giving out light and soot
Date posted:
October 15, 2019
-
Water has a boiling point of 100oC while hydrogen chloride has a boiling point of -115oC. Explain
Date posted:
October 15, 2019
-
Between aluminium and copper which one is a better conductor? Explain
Date posted:
October 15, 2019
-
Using dots and crosses to represent electrons, draw the structures of the following:
(a) Phosphorous chloride (PCl3)
(b) Hydroxonium ion (H3O+)
Date posted:
October 15, 2019
-
a. Eleza maana ya lakabu.
b. Huku ukitoa mifano mwafaka, taja asili tano za lakabu.
c. Eleza sifa saba za lakabu.
d. Eleza umuhimu wa lakabu katika jamii
Date posted:
October 15, 2019
-
Soma Shairi kisha ujibu maswali.
(a) Kwa kuzingatia mishororo miwili ya mwisho kila ubeti, eleza bahari ya shairi hili.
(b) Onyesha kero zinazosababishwa na mvua.
(c) Eleza kanuni zilizofuatwa kutunga shairi hili.
(d) Onyesha namna mshairi alivyotumia idhini yake.
(e) Andika ubeti wa kwanza kwa lugha ya nathari.
(f) Taja mbinu mbili za lugha zilizotumiwa katika shairi hili.
(g) Andika maana za maneno haya kulingana na muktadha wa shairi.
(i) kutwa na kucha
(ii) kuicha mvua
Date posted:
October 15, 2019
-
Draw a diagram to show bonding in an ammonium ion. (N = 7, H = 1)
Date posted:
October 15, 2019
-
Eleza jinsi mwandishi alivyofanikisha mbinu ya kisengere nyuma.
Date posted:
October 15, 2019
-
"...wanahofia kusema wasije wakavikata viganja vinavyowalisha..."
a. Eleza muktadha wa dondoo hili.
b. Taja maudhui yanayojitokeza katika dondoo hili na ueleze.
c. Kwa kutoa hoja kumi, eleza namna maudhui uliyotaja hapo juu (2b) yanavyojitokeza katika riwaya.
d. Eleza sifa nne za msemaji
Date posted:
October 15, 2019
-
Study the information in the table below and answer the questions that follow.
(The letters do not represent the actual symbols of the elements)
(a) What is the general name given to the group in which elements P, Q and R belong?
(b) Explain why P has the highest ionization energy
(c) Write a balanced chemical equation for the reaction between element Q and water
Date posted:
October 15, 2019
-
"Na mwamba ngoma huvuta wapi?"
a. Eleza muktadha wa dondoo hili.
b. Tambua tamathali mbili za sauti zilizotumika katika muktadha huo.
c. Fafanua sifa za msemewa wa maneno.
d. Thibitisha ukweli kuwa kila mwamba ngoma huvuta kwake ukirejelea Tamthilia nzima ya Kigogo.
Date posted:
October 15, 2019
-
Akifisha sentensi hii:
Lo ni nani huyo anayeshambulia mwanangu jirani yangu aliuliza kwa hasira nyingi.
Date posted:
October 15, 2019
-
Unda Nomino kutokana na vitenzi vifuatavyo:
Dhulumu
Tubu
Date posted:
October 15, 2019
-
Andika visawe vya maneno yaliyopigiwa mstari katika sentensi ifuatayo:
Lupita ndiye alitakadamu upelelezi wa shamba hili.
Date posted:
October 15, 2019
-
The information in the table below relates to elements in the same group of the periodic table.
Study it and answer the question that follows.
Which element has the highest ionization energy? Explain
Date posted:
October 15, 2019
-
Tunga sentensi ukitumia kihusishi cha wakati.
Date posted:
October 15, 2019
-
Tambua yambwa katika sentensi ifuatayo na ueleze ni za aina gani.
Wazazi waliwanunulia wanafunzi bora zawadi nyingi kwa hundi.
Date posted:
October 15, 2019
-
The table below shows elements A, B, C, E, F, and G. Elements in group X have a valency of 2 while elements in group Y have a valency of 1. Use the table to answer the questions that follow:-
(i) Atomic radius increases from A to C and from E to G. Explain
(ii) Explain the difference in the atomic and ionic radii of group X elements
(iii) Elements C and G belong to the same period. Explain why the atomic radius of C is
greater than that of G
(iv) Give the formula of the compound formed when B and F react
(v) What type of bonding is formed in the compound above? Explain
(vi) Starting with the least reactive, arrange the elements in group Y in the order of reactivity.
Explain:
Date posted:
October 15, 2019
-
Eleza maana tatu za sentensi hii.
Chakula kingine kimeliwa na wageni
Date posted:
October 15, 2019
-
Tumia kiunganishi seuze/sembuse katika sentensi.
Date posted:
October 15, 2019