Why does the first ionisation energy of atoms generally increase across a period?
The first ionisation energy is defined as the energy required to remove one mole of electrons from each atom of a mole of gaseous atoms. As we go along a period in the periodic table, the atomic number increases. As the atomic number increases, the number of protons in the nucleus increases. This causes the electrostatic attraction between the nucleus and the outermost electron to generally become stronger across a period.
Related Chemistry A Level answers
All answers ▸Describe and explain the reactivity trend of the Group 2 elements
Why does ionisation energy of elements generally decrease as you move down a group in the periodic table?
3-methyl pent 2 ene reacts with HBr to form two products. Which of these products is the minor and major product and why?
Define Electronegativity