Periodicity and reactivity trends OCR A Level

Front

What is the periodic trend for ionization energy across a period?

Back

Ionization energy generally increases across a period from left to right due to increasing nuclear charge and decreasing atomic radius.

Front

What is the periodic trend for ionization energy down a group?

Back

Ionization energy generally decreases down a group due to increasing atomic radius and shielding effect.

Front

Define valence electrons.

Back

Valence electrons are the electrons in the highest energy level of an atom that are involved in chemical bonding.

Front

What is the relationship between atomic size and ionization energy?

Back

As atomic size increases, ionization energy decreases because the outermost electrons are further from the nucleus and experience less attraction.

Front

Explain why Francium has the lowest first ionization energy in Group 1.

Back

Francium has the lowest first ionization energy because its one valence electron is far from the nucleus, requiring less energy to remove it.

Front

Which element has a higher ionization energy: Silicon or Lead?

Back

Silicon has a higher ionization energy than Lead due to its smaller atomic size and greater effective nuclear charge.

Front

True or False: It is easier to remove a second electron from a sodium atom than the first.

Back

False. It is generally harder to remove a second electron due to increased positive charge in the nucleus after the first electron is removed.

Front

What is the significance of the modern periodic table in understanding element properties?

Back

The modern periodic table organizes elements by increasing atomic number, revealing trends in properties such as ionization energy, electronegativity, and atomic radius.

Front

Define ionization energy.

Back

Ionization energy is the energy required to remove an electron from a gaseous atom or ion.

Front

What happens to the ionization energy of elements as you move from left to right across a period?

Back

Ionization energy increases as you move from left to right across a period.