Wisdom Link Tutor

*AMAZING CHEMISTRY FACTS FROM WISDOM LINK TUTORIAL*

*(1)* The only solid elements that assume liquid form ​at room temperature are bromine and mercury. However, you can melt gallium by holding a lump in the warmth of your hand.

*(2)* Unlike many substances, water expands as it freezes. An ice cube takes up about 9% more volume than the water used to make it.

*(3)* If you pour a handful of salt into a full glass of water, the water level will actually go down rather than overflowing the glass.

*(4)* Similarly, if you mix half a liter of alcohol and half a liter of water, the total volume of the liquid will be less than one liter.

*(5)* There is about 0.4 pound or 200 grams of salt (NaCl) in the average adult human body.

*(6)* A pure element takes many forms. For example, diamond and graphite both are forms of pure carbon.

*(7)* Many radioactive elements actually glow in the dark.

*(8)* The chemical name for water (H2O) is dihydrogen monoxide.

*(9)* The only letter not appearing on the periodic table is J.

*(10)* Lightning strikes produce O3, which is ozone, and strengthen the ozone layer of the atmosphere.

*(11)* The only two non-silvery metals are gold and copper.

*WISDOMLINK MATHEMATICAL TRICKS*

*(1)* Suppose we need to find the square root of large numbers such as 4489 without the use of calculator

Step 1: The unit digit in this number is 9, which can be a unit digit of its square root number such as 3 or 7. Because 32 is 9 and 72 is 49.

Step 2: Now let us consider the first two digits that is 44 which comes between the squares of 6 and 7 because 62 < 44< 72

Step 3: We can assume that the ten’s digit of the square root of 4489 is the lowest among the two numbers i.e. 6 and we need to find the unit digit of the square root of the number 4489.

Step 4: Now, we need to find between 63 or 67 which is the square root of 4489.

Step 5: Since the ten’s digit is 6 and the next number is 7, we need to multiply both the numbers like 6 x 7 = 42 and since 42 is less than 44.

Step 6: Square root of 4489 will be the bigger number between 63 and 67 i.e. 67.

Therefore, √4489 = 67

*(2)* When counting a percentage value (e.g 40% of 300). Divide both side by 10 and multiply the result

(4 x 30)= 120

*(3)* To multiply 9 by 5, fold down the fifth finger from the left. Count fingers on either side of the "fold" to get the answer. In this case, the answer is 45.

To multiply 9 times 6, fold down the sixth finger, giving an answer of 54.

*(4)* The 11 Rule
This is a quick way to multiply two-digit numbers by 11 in your head.

Separate the two digits in your mind.
Add the two digits together.
Place the number from Step 2 between the two digits. If the number from Step 2 is greater than 9, put the one's digit in the space and carry the ten's digit.
Examples: 72 x 11 = 792.

57 x 11 = 5 _ 7, but 5 + 7 = 12, so put 2 in the space and add the 1 to the 5 to get 627.

*(5)* If you multiply 6 by an even number, the answer will end with the same digit. The number in the ten's place will be half of the number in the one's place.

Example: 6 x 4 = 24.