2.4 Study the attempt of the “Mad Scientist”. He tried to calculate 28 428 ÷ 138. Is his answer correct? Type Yes or No. Where did he make mistakes? Name two mistakes he made, describe them in words. Then type the correct answer. (It is not necessary to show how you arrived at your answer). Type all of your answers in the textbox below. Click on the button to view the calculation in a larger format.       (5)

The “Mad Scientist” wanted to expand his knowledge further and then read more about the strong door in his laboratory. He then finds out, the door is not just made of pure iron. But also, out of aluminum. Aluminum has a mass of 26,9815.

5.3.2 Study the following picture and answer the questions that follow:   To calculate the number of neutrons of the aluminum atom, the “Mad Scientist” found the following formula on the internet: Number of neutrons = Mass number – Atomic number   Use the formula to calculate the number of neutrons in the aluminum atom. Show all your steps.   Click on the button.   (3)

5.  Study the following picture and answer the questions that follow:      

5.1.1 If the number of protons doubled, how many protons would there be?(Write a numbers sentence/calculation and give the correct answer. (2)

3.4 Convert the following mixed number to an improper fraction. (5 and 5/6) (1)

3.8 Convert 0,75 to a common fraction in its most simplified form. (1)

The next thing you notice is a machine with a dial.  On the dial there are the missing decimal and whole numbers.  You KNOW it must mean something, so you complete the missing decimal numbers and symbols.

 2.1  Study the attempt of the “Mad Scientist”.      Is the answer correct? Type Yes or No.  If not where did he go wrong? Please name two mistakes that he made and correct those mistakes for him.   Type all of your answers in the textbox below. Click on the button to view the calculation in a larger format. (5)

5.3.1 The “Mad Scientist” wants to work out the total of the masses of the two atoms (iron /aluminum- 5.85 + 26.9815). He does this in the following two ways. Which method is correct? Why do you say so? (2)   Method 1:   Method 2:       Click on the button to view the calculation in a larger format.