Answer:
Oil is a fossil fuel and timber or wood and wind is not. Hope this helps!
3 is C i believe, and as for 4 minerals are solid, natural.. that's about all I can say...
Answer:
the compound contains C, H, and some other element of unknownidentity, so we can’t calculate the empirical formula
Explanation:
Mass of CO2 obtained = 3.14 g
Hence number of moles of CO2 = 3.14g/44.0 g = 0.0714 mol
The mass of the carbon in the sample = 0.0714 mol × 12.0g/mol = 0.857 g
Mass of H2O obtained = 1.29 g
Hence number of moles of H2O = 1.29g/18.0 g = 0.0717 mol
The mass of the carbon in the sample = 0.0717 mol × 1g/mol = 0.0717 g
% by mass of carbon = 0.857/1 ×100 = 85.7 %
% by mass of hydrogen = 0.0717/1 × 100 = 7.17%
Mass of carbon and hydrogen = 85.7 + 7.17 = 92.87 %
Hence, there must be an unidentified element that accounts for (100 - 92.87) = 7.13% of the compound.
1. it’s use for our food in like microwaves and ovens
2. airplanes are guided by radar waves,
3.the tv is used by electromagnetic waves
4. they are used in heaters,
5.infrared cameras which detect people in the dark
6.Allows airport security to observe the internal contents of objects and luggage using airport scanners
7.doctors use electromagnetic waves in x-rays
