What is the mass number of an atom that contains 12 protons, 14 neutrons, and 12 electrons? * 10 points
2
26
24
168

The mass number of an atom : 26

Given

12 protons, 14 neutrons, and 12 electrons

Required

The mass number

Solution

Inside the atom there are 3 sub-particles, namely protons, neutrons and electrons. Protons and electrons are present in the atomic nucleus while electrons move around the atomic nucleus through energy levels in the atomic shell

Atomic number = number of protons = number of electrons

Mass number = number of protons + number of neutrons

Input the value :

Mass number = 12 + 14

Mass number = 26

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.