A detector close to a sample of radioactive material records 76 counts per second (cps).
Precisely 2 days later the count rate has fallen to 22 cps.The count rate due to background
radiation, taken immediately before and after the experiment, averaged 4 cps. The half-life of the
material is:
2. Question | Biology
A student observed a plant cell through a microscope and made an accurate drawing of the cell.
If her drawing was 80 mm in diameter and had a magnification of ×2000, what was the real
diameter of the cell?
3. Question | Integrated Science
Many leaves are adapted to photosynthesise effectively by having:
4. Question | Chemistry
More collisions between particles are likely to happen if a solution is made:
5. Question | Mathematics
In coordinate geometry, the equation of the x-axis is
6. Question | Information Technology
All the following are examples of hardware interfaces EXCEPT __________.
7. Question | Mathematics
In the Venn diagram above, the shaded
portion represents
8. Question | Principles Of Accounts
The ABC Company deposited a Cheque received from Mr. Murray for $300.00. How must this transaction be recorded in ABC′s book?
1. Credit the Cash Book $300
2. Credit Murray′s Account
3. Debit the Bank Account
4. Debit the Cash Account
9. Question | Chemistry
When metals react with acids they give a salt and:
10. Question | Chemistry
If the relative atomic mass (RAM) = 1 for hydrogen and 16 for oxygen, the formula mass for
H2O2 is:
11. Question | Chemistry
To make cell walls, plants must have:
12. Question | Biology
Which one of the following foods contains the most energy per 100 g?
13. Question | Mathematics
$x is divided among three boys, Ryan,
Keith and Andrew, in the ratio 2 : 3 : 7,
respectively.
If Andrew gets $15 more than Keith,
what is the value of x ?
14. Question | Mathematics
The range of values of v when
5 - v ≤ 2v - 1 is
15. Question | Social Studies
Healthy individuals are beneficial to a country′s development because such individuals are likely to be
16. Question | Mathematics
The perimeter of a rectangle is 26 cm. The rectangle is converted to a square by tripling the width and taking a quarter of the length. What is the perimeter of the resulting square?
17. Question | Biology
A balanced diet is one which:
18. Question | Chemistry
In the reactivity series of metals the order is: sodium, calcium, magnesium, aluminium, which means that the most reactive metal is:
19. Question | Chemistry
The only one of the following which is NOT a change of state is:
