What evidence would support maria's claim that the fossilized remains are that of a bird, class aves, instead of a turtle, class reptilia? a) the eggs b) a backbone c) a keeled sternum d) warm-bloodedness

The correct answer is - C)  a keeled sternum.

The birds and the turtles have multiple differences in their anatomy, and of the biggest is that the birds have wings, while the turtles don't. Because of the development of the wings, the birds have keeled sternum. The keeled sternum in the birds is an adaptation that supports the ability for flying. The kelp in the birds runs axially along the midline of the sternum, extending outwards, in a perpendicular manner to the plane of the ribs. The turtles lack this kind of anatomy, so it is a safe bet to state that the fossil is a bird one if it includes a keeled sternum.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.