Question

6.
number and name of that element.
Find the focal length (1) of a concave mirror with R=20 cm..
Write the benefits you observe, if the plaster of naris wmenat​

Answer 1

Answer:

• element of atomic number 6 is carbon.
• focal length is 10 cm.

Answer 2

Answer:     R=2f by this formula we can say that

20=2f   =>f=10cm

number of element is 6 .name is carbon

benifits of plaster of paris : 1) for making toys

                                             2)for supporting the fractured parts