A student was measuring the ratio of a circle’s circumference and diameter. They found the circumference to be 6.28 cm and the diameter to be 1.8 cm. The actual ratio (circumference divided by diameter) was 3.14. What was their percent error?

Percent error =   11%

Explanation:

Given data:

Circumference = 6.28 cm

Diameter = 1.8 cm

Actual ratio of circumference and diameter = 3.14

Percent error = ?

Solution:

Formula:

Percent error = ( measured value - actual value / actual value) ×100

Measured value:

Measured ratio of circumference and diameter = 6.28 cm/1.8 cm

Measured ratio of circumference and diameter = 3.49

Now we will put the values in percent error formula.

Percent error = (3.49 -3.14 / 3.14) ×100

Percent error =   (0.35 / 3.14) ×100

Percent error =   0.11×100

Percent error =   11%

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.

d.) circle motion requires a force to give it a centripetal acceleration.