Question

1)

Atom A and atom B have the same number of protons and the same number of neutrons but have a different number of electrons. Therefore, _______________.

		atoms A and B must be different isotopes of the same element
		one or both of atoms A and B must be an ion
		atom A must be electrically neutral and atom B must be a cation
		atoms A and B must be different elements

2)

Which one of these would be a form of evidence that supports the endosymbiont theory?

		Chloroplasts and mitochondria are found in all eukaryotic cells.
		Chloroplast and mitochondrial ribosomal RNA sequences are similar to those of certain bacteria.
		Chloroplasts and mitochondria contain linear DNA molecules.
		Chloroplasts and mitochondria possess flagella similar to those of some bacteria.

3)

Choose from the following list of words to complete the paragraph below. Not all terms will be used, and none of them can be used more than once.

positive     intermediate     free   negative   substrate   product   activation   thermal

An enzyme reduces the energy of a reaction, causing it to occur more frequently at a given temperature than it would otherwise. This does not alter the energy of the reactants or products. If the ΔG of a reaction is. , the reaction is spontaneous. Reactions that have a common and are part of the same pathway are energetically coupled since the  ΔG for the pathway is the sum of the  ΔGs of the individual reactions.

Answer 1

Ans. (c) atom A must be electrically neutral and atom B must be a cation

According to the given information, we know that the 2 elements cant have the same no. of protons as the no. of protons represents atomic no. and the isotopes of any of the element will have the similar atomic no., which means they will have same no. of protons but will have distinct atomic mass i.e. different no. of neutrons. Ions can only have the different no. of electrons and same no. of protons and neutons. As ions are the charged particles and atoms are basically neutral molecules becuase they have both equal no of electron and protons.

Thus according to the given question the One of the atom must be neutral and other must be the same element with ionic character.