Science periodic table test Flashcards
describe the periodic table
The periodic table is a table with all the known elements, it is placed in a way so scientists can predict the reactions between elements using the vertical lines to find the specific elements and their valance electrons.
how is the elements represented?
they are represented by their chemical symbol that consist of one to two letters, examples are Oxygen (O) and sodium (Na)
Outline the different scientists who contributed to the periodic table.
Last names: mendeleev, Lothar meyer, Moseley
Dmitri Mendeleev was the creator of the periodic table but Julius Lothar Meyer also helped. Henry Moseley improved the table to what it is now.
What trends can be notisedf in the periodic table?
The element’s atomic number increases the further down we go on the table which means more protons neutrons and electrons that can lead to stronger reactions. We also see that elements in the same group tend to have the same reactions
Howe do the metalls change across the table?
The metal properties do tend to change from up to down and left to right but the further right you go the more conductive mettals are there.
Describe the properties of the elements in group 1.
Group 1: Are the alkali metals, these metals are highly reactive to the elements in elements 4 or the groups higher. (not the 8th group) and have a low melting point and are shiny
Describe the properties of the elements in group 7.
The Halogens elements with 7 valance electrons are highly reactive because they only need 1 electron to be filled, The halogens are gases but also can be solid, halogens tend to make acidic compounds.
Describe the properties of the elements in group 8.
Noble gasses are elements that tend to be only in gas form and are filled with 8 valence electrons, these elements are very hard to react with and only react in special conditions. They are coloor less odorless gasses that only exist as a single atom.
what observations tend to happen between halogens and alkali metals when they react?
When halogen elements and Alkali metals react they react strongly to each other and usaly form table salts.
explain why and how the reactivity changes down the periodic table.
The reactivity of an element depends on the size/weight of the atom because when an atom is heavier it tends to have more shells and the valence electrons are further from the nucleus, which makes it way easier to give/take electrons. This in conclusion makes a bigger reaction between elements. this increases the further down the table you go.
