Chemistry HESI A2 Quizlet

Correct Answer: C

Rationale: The correct answer is C: +2. Alpha radiation particles are helium nuclei consisting of 2 protons and 2 neutrons, giving them a charge of +2. This charge is due to the presence of 2 protons, which are positively charged particles. Choice A (-2) is incorrect as alpha particles are positively charged. Choice B (0) is incorrect as alpha particles have a positive charge. Choice D (+1) is incorrect as alpha particles have a charge of +2 due to the presence of 2 protons.

Correct Answer: C

Rationale: The correct answer is C: Element. An element is the simplest form of a substance that cannot be broken down further by chemical means. It consists of only one type of atom. Compounds (A) are made up of two or more different types of atoms chemically bonded. Mixtures (B) contain two or more substances physically mixed but not chemically bonded. Molecules (D) are combinations of atoms, which can be either elements or compounds.

Correct Answer: A

Rationale: The correct answer is A: Unequal sharing of electrons. In a covalent bond, when two different atoms with different electronegativities come together, one atom attracts the shared electrons more strongly than the other, leading to an uneven distribution of electron density. This results in a dipole moment where one end of the bond is slightly positive and the other slightly negative. Choices B, C, and D are incorrect because in covalent bonds, electrons are not fully transferred or exchanged, but rather shared between atoms, leading to the creation of a dipole due to the unequal sharing of electrons.

Correct Answer: B

Rationale: The correct answer is B: Ionic & covalent. Ionic bonding involves the transfer of electrons between atoms, resulting in the formation of positive and negative ions. Covalent bonding involves the sharing of electrons between atoms. These two types of bonding are distinct in their electron behavior and resulting bond strength. Choice A is incorrect as hydrogen bonding is a type of intermolecular force, not a primary chemical bond. Choice C is incorrect as hydrogen bonding is not a primary chemical bond and ionic bonding involves the transfer of electrons, not hydrogen atoms. Choice D is incorrect as metallic bonding involves the sharing of electrons in a sea of electrons, not between specific atoms.

Correct Answer: B

Rationale: The correct answer is B: Chemical reaction. In a chemical reaction, bonds are broken and new bonds are formed to create new chemical compounds. The process involves the rearrangement of atoms to form different substances with unique properties. Physical reactions (choice A) involve changes in physical state or appearance without altering the chemical composition. Nuclear reactions (choice C) involve changes in the nucleus of an atom, leading to the formation of different elements. Mechanical reactions (choice D) involve physical forces but do not result in the formation of new chemical compounds.