Group vs. Period [ENDORSED]

[Kassidy Patron 1L]

Hi! I'm a little confused about the difference between groups and periods. Are groups how the periodic table is split into columns (vertically) and periods are the rows (horizontally)? Also, can you explain the relationship between group & period and atomic radii?

[joshua_quinn_1C]

Hi! Yes, groups are the vertical columns while periods are the rows. As for atomic radii, the radius of an atom gets larger as you go down the group and smaller as you go across the period.

[Meghan Spoeri 2D]

hi! going off the previous answer, as you go down a group (top to bottom), the size of the atomic radius increases. This is because you are adding more energy levels as you go down the group, which makes the atom larger. Each additional shell that you add becomes farther from the nucleus, increasing the atomic radius. As you go across a period (left to right), the size of the atomic radius decreases. This is due to the effective nuclear charge increasing, as the number of protons increase. This causes the nucleus to have a stronger positive charge, which pulls in the outer electrons, therefore making the atom smaller.

[Alexis Shen 2G]

What my other previous two peers said is completely right! As you go across the period (row), the atomic radius gets smaller and smaller. This means that an element at the end of the period has a much smaller radius than the element at the beginning because of the nuclear charge. The nuclear charge is the attraction of the electrons to the nucleus and because as we go across a period there are more protons, there is a higher nuclear charge. Going down a period increases the atomic radius because we're adding more shells.

[Martha Avila 1I]

Hello! So just to emphasize what all the other students have stated, a group is a vertical column while a period is a horizontal row. Now in terms of atomic radius there is a trend that you can remember. As you move across a period the atomic radius will decrease and as you move down a group the atomic radius will increase. There are some helpful problems on the Achieve HW #2 that should solidify your understanding of this concept. Hope this helped!

[605778346]

Periods are categorized horizontally in rows across the tables. Groups are separated in vertical columns down the table. Atomic size decreases across the period and increases down the group.

[Reagan Feldman 1D]

Periods on the periodic table are the horizontal rows. In terms of atomic radius, the size decreases as you move across a period. Groups are the vertical columns, in which atomic radii increase as you move down a group.

[SerenaSabedra]

Groups are vertical and periods are horizontal. Atomic radii will increase as you go down a group because the number of shells of electron increases, which of course increases the size of the atoms. Atomic radii decreases as you go right across a period. This is due to the increase of protons and thus an increase in effective nuclear charge, which brings the electrons closer into the atom and decreases its size.

[Skylar Lo 2C]

Periods are the rows while groups are the columns. Atomic radius will decrease across a period and increase down groups.

[Emily Quill 2H]

Hi! Periods are the rows across and groups are the columns on the periodic table. Also the atomic increases the farther to the left-bottom corner you go on the table.

[Sidharth Paparaju 3B]

Periods are the rows and Groups are the column. As you go to the right of a period, radii decreases and as you go down a group, radii increases.

[Erin Chin 1L]

Hi there! Groups are the vertical columns and periods are the rows in the periodic table. As for the atomic radii trend, when you go across the period (horizontal), the radius of an atom decreases, and as you go down the group (vertical), it increases.

[Erin Woolmore 1C]

Groups are the columns, and periods are the rows. As for the relationship between groups/periods and atomic radii, just think of attraction between an element's electrons and its nucleus. Atomic radius increases from right to left and up to down on the periodic table. The valence shells in the noble gases are filled, so therefore the electrons are more tightly held to the nucleus. Conversely, the alkali metals only have 1 electron in their valence shell, so it is toward the outer edge of the electron cloud. Hope this helps!