Why does ionization energy increase as you move across a period?

Answer 1

This is because the atom's radii is getting smaller so the electrons are getting closer to the nucleus, which means there is a greater attraction on these electrons, causing it to be harder to remove the electrons.

Answer 2

Elements on the right of the chart want to take others atom's electron (not given them up) because they are close to achieving the octet. The means it will require more energy to remove the outer most electron. Elements on the left of the chart would prefer to give up their electrons so it is easy to remove them, requiring less energy (low ionization energy).

source: http://www.geocities.com/capecanaveral/lab/4097/chem/chap4/periodictrends.html

Answer 3

The way the Periodic Table is organized, you have metals with just one valance electron on the extreme left of the table, and as you move across the table to the right, you add one more electron with each space you move, not counting the transition state elements which are a complicating factor. The more valance electrons there are, the more you will have to remove in order to satisfy the octet rule and arrive at a stable arrangement of eight electrons in the outer shell. When you remove an electron, the atom in question becomes positively charged, and with each additional electron that you remove, the positive charge becomes larger. And of course, opposite charges attract. So the positively charged ion attracts negatively charged electrons, hence, more energy is needed to remove them.

Answer 4

The nuclear charge Z increases, and unlike electrons in lower shells, electrons in the same shell do not fully screen the nuclear charge from each other.

Answer 5

Why does ionization energy tend to increase as you move across a period?

Answer 6

When we move from left to right, ionization enthalpy increases. this is because of increasing nuclear charge which holds outermost electrons.