A ‘gold medal’ used in events such as the Olympic Games is made from a silver–nickel alloy with a coating of a gold–silver alloy.The mass of the medal is 256…

The reaction between hydrogen and nitrogen in the presence of an iron catalyst is known as the Haber process. It is a reversible reaction. The energy profile for this reaction…

Some rabbits have a genetic condition. The dominant allele codes for this condition. A homozygous dominant rabbit mated with a rabbit that did not have the condition. They had three…

In a sale, the normal price of a camera is reduced by 20%. The sale price of the camera is £180. Which expression gives the normal price of the camera?…

An electric fan heater contains a heating element and a motor that drives the fan. The circuitdiagram is shown.At first, the switch is open and the current in the motor…

Hot, concentrated aqueous sodium hydroxide and chlorine react as shown in the equation:6NaOH + 3Cl2 → 5NaCl + NaClO3 + 3H2OWhich of the following statements is/are correct?1 Chlorine has oxidation…

Scientists are using human stem cells to develop treatments for a wide variety of healthconditions.Two types of stem cell that are available for this work are: stem cells collected from…

Which one of the following is a simplification of 2-2x+1 / 4x2+4x+1 ? Answer: 4) A 2- 2x+1 / 4x2+4x+1We can simplify the denominator24x 4x + 1 = (2x +…

A supermarket has a large open-topped deep freezer to keep products frozen but still visible to customers. Which statement about the air in this freezer explains why the products remain…

A sample of an element consists of two isotopes. The relative abundance of each isotope isshown in the table.What is the relative atomic mass of the element in this sample?…