Afishing boat accidentally spills 3.0 barrels of diesel oil into the ocean. each barrel contains 42 gallons. if the oil film on the ocean is 2.5 × 102 nm thick, how many square meters will the oil slick cover?

Number of barrels are 3.0. Each barrel contains 42 gallons of oil. Thus, total volume of oil will be 42×3=126 gallons.

Converting gallons into m^{3}

1 gallon=0.00378 m^{3}

Thus, 126 gallons=0.4769 m^{3}

Thickness of oil film is 2.5\times 10^{2} nm, converting it into meters as follows:

1 nm=10^{-9} m

Thus,

2.5\times 10^{2} nm=1.5\times 10^{-7}m

Now, volume V of oil is related to area A and thickness T as follows:

V=A×T

rearranging,

A=\frac{V}{T}=\frac{0.4769 m^{3}}{2\times 10^{-7}m}=2.38\times 10^{6}m^{2}

Thus, square meters of oil will be 2.38\times 10^{6}m^{2}

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.