Explanation:
Carbon-12 atoms have stable nuclei because of the 1:1 ratio of protons and neutrons.
Carbon-14 atoms have nuclei which are unstable. C-14 atoms will undergo alpha decay and produce atoms of N-14. Carbon-14 dating can be used to determine the age of artifacts which are not more than 50,000 years old.
90 minutes is 1.5 hours.
5 kW * 1.5 hours = 7.5 kWh
8c/kWh * 7.5 kWh = 60 cents
it exists as atom or ion but not as sodium molecule. So there is no any sodium sodium bonding between two sodium atoms. Sodium combines with other element or group to form compounds of sodium like sodium chloride ,sodium carbonate ,sodium sulphate etc. Sodium has symbol Na and its atomic no. is 11 .
An endothermic process is a process that needs energy in order to proceed. This is the opposite of exothermic which is a process of releasing energy. During an endothermic process, the temperature of the system is increased thus exciting the molecules and allowing them to move faster. This will cause liquid to vaporize.