Be sure to answer all parts. calculate the mass of each of the following: (a) a sphere of gold with a radius of 12.5 cm. (the volume of a sphere with a radius r is v = (4/3)πr3; the density of gold is 19.3 g/cm3.) × 10 genter your answer in scientific notation. (b) a cube of platinum of edge length 0.049 mm (density = 21.4 g/cm3). × 10 genter your answer in scientific notation. (c) 67.1 ml of ethanol (density = 0.798 g/ml). g

(a)

The radius of the sphere is:

r = 12.5 cm

So the volume of the sphere of gold is

The density of gold is

So the mass of the sphere is

(b)

The length of one side of the cube is

L = 0.049 mm = 0.0049 cm

So the volume of the cube of platinum is

The density of platinum is

So the mass of the cube is

(c) 53.5 g

The volume of the ethanol is

V = 67.1 mL

While its density is

d = 0.798 g/mL

So the mass of the ethanol is

atomic = no of protons.

mass number-atomic number = neutron number

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)