Select the most appropriate answer from the list of options given in (a), (b), (c) or (d) for each question. 1. with respect to controlling fluids in pipework, the function of a butterfly valve is to: (a) regulate the flow rate of fluid through a pipe but has a non-linear flow response. (b) prevent reverse flow of fluid through a pipe. (c) completely stop fluid flow between two points in a pipe due to their linear flow response.. (d) throttle the flow of fluid through a pipe and have an approximately linear flow response between opening angles of between 45° and 90°.

the volume of fluid displaced would equal the volume of the gas. use a gas syringe - this is a laboratory instrument that can be used to withdraw a certain volume of gas from a closed system or to measure the volume of gas from a chemical reaction.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3