Chem Chapter 5 – Flashcards

atomic number

atomic radius

further space between electrons and nucleus, giving it less of a pull

they have less of a need for electrons, so they won't have less electronegativity

measure of ability of an atom to attract electrons

energy required to remove an electron from an atom

energy change that occurs when an electron is acquired by a neutral atom

distance between nucleus and electrons

left - down

up - right

first 2 groups form positive ions

15-17 groups. They gain electrons because gaining electrons makes them closer to being like a noble gas - easier to gain than lose a lot of electrons.

alkali metals- silvery and soft

alkaline-earth metals: less reactive but too reactive to be found in nature

main-group elements: nonmetals and metalloids

halogens- most reactive nonmetals and react with metals

lanthanides- shiney actinides- radioactive

transitional metals

created a table in which elements with similar properties were grouped together

discovered that elements fit into patterns better when arranged in atomic number rather than weight

repeating patterns/ elements in atomic mass/electronegativity/ atomic number order and were also grouped with similar atoms

number- number of protons mass- weight of atom

a, ns1

Their location in the periodic table indicates that phosphorus and sulfur are nonmetals and sodium is a metal. Nonmetals are a group with characteristic properties, so phosphorus and sulfur are the most similar. Phosphorus and sulfur both have valence electrons in the p orbitals and sodium does not.

In the periodic table, elements in the same column or group have similar properties. Because helium and xenon are in the same group, they have similar properties.

Nuclear charge is the attraction an atomic nucleus has on the electrons surrounding it. As you move from left to right across a period, the atomic number increases, and therefore the number of protons in the nucleus increases. The more protons within a nucleus, the greater is the nuclear charge. A greater nuclear charge pulls the electrons closer to the nucleus, decreasing the atomic radius.

decreases across a period because there are more electrons as you go across, causing the atoms to become negative which makes the atom smaller bc there is more of a pull towards the positive nucleus. increases down a group because there is an increase of energy levels, giving you more shielding so the electrons can't pull towards the nucleus as much (positive atoms)

increase across a period because they are closer to filling their outer shells so there is more of a need for electrons decrease down a group because there are more energy levels so there is further space between the protons and electrons, giving it less of a pull and more shielding.

increases across a period bc there are more of a pull on the electrons, making it harder to remove an electrons, causing it to use more energy decreases down a group bc there is less of a pull as you go down, making it easier to remove electrons