Chemistry Regents Review: Practice Quiz

Electrons have a negative charge, making them the correct answer. Protons carry a positive charge while neutrons have no charge, and positrons are the antimatter counterpart of electrons.

The symbol 'Na' is derived from the Latin name 'Natrium' and is the accepted symbol for Sodium. The other options represent either different elements or incorrect symbols.

Sublimation is the process by which a solid converts directly to a gas without passing through the liquid phase. Evaporation involves a liquid turning to a gas, condensation is from gas to liquid, and melting is from solid to liquid.

The Law of Conservation of Mass states that the total mass of the reactants is equal to the total mass of the products in a chemical reaction. This principle is crucial for balancing chemical equations.

The periodic table organizes elements by increasing atomic number and groups elements with similar chemical and physical properties together. It provides a framework for predicting element behavior and periodic trends.

The molar mass of CO2 is calculated by adding the atomic mass of carbon (12 g/mol) to twice the atomic mass of oxygen (2 x 16 g/mol), which equals 44 g/mol. This calculation is a basic application of molar mass determination.

The Bronsted-Lowry theory defines an acid as a substance that donates a proton (H+ ion) during a chemical reaction. This differentiates acids from bases, which accept protons.

Heating sodium bicarbonate causes it to decompose, releasing carbon dioxide gas along with other products. This reaction is a common example of thermal decomposition in chemistry.

A catalyst speeds up a reaction by providing an alternative pathway with a lower activation energy. It is not consumed in the reaction and does not change the reaction's equilibrium position.

Across a period, increased nuclear charge pulls electrons closer to the nucleus, thereby decreasing the atomic radius. This is a fundamental periodic trend that influences many chemical properties.

Noble gases have a completely filled valence shell, which makes them chemically inert. This full electron configuration is a key reason for their lack of reactivity.

According to Boyle's Law, if the temperature remains constant, a decrease in volume results in an increase in pressure. This inverse relationship is vital for understanding gas behavior.

Photosynthesis is an endothermic process that absorbs energy from sunlight to convert carbon dioxide and water into glucose. In contrast, combustion and rusting are exothermic reactions that release energy.

In redox reactions, oxidation refers to the loss of electrons, while reduction refers to the gain of electrons. Recognizing these electron transfer processes is crucial for solving redox problems.

The coefficient in a balanced equation indicates the number of moles of the corresponding substance. This value is essential for performing accurate stoichiometric calculations in chemical reactions.

First, calculate the moles of CaCO3: 2.00 g / 100 g/mol = 0.02 mol. Since the reaction CaCO3 → CaO + CO2 produces one mole of CO2 per mole of CaCO3, the mass of CO2 is 0.02 mol x 44 g/mol = 0.88 g.

Using Boyle's Law (P1V1 = P2V2), when the pressure doubles from 1 atm to 2 atm at constant temperature, the volume is halved from 3.0 L to 1.5 L. This inverse relationship between pressure and volume is fundamental for ideal gases.

According to the balanced equation, one mole of O2 produces two moles of H2O. Therefore, 4.0 moles of O2 yield 4.0 x 2 = 8.0 moles of water. This demonstrates the mole-to-mole conversion in stoichiometry.

Hess' Law states that the overall enthalpy change is the sum of the individual steps. Adding -50 kJ and +30 kJ results in an overall ΔH of -20 kJ for the reaction A → C.

Transition metals possess partially filled d orbitals which allow electrons to undergo d-d transitions. These transitions absorb certain wavelengths of light, resulting in the brilliant colors observed in their compounds.