Periodic Table Trends and Isotopes Flashcards
Aligned with Kognity
Define atomic number
Atomic number = Proton number
What are the terms for the number of protons and neutrons?
Mass number, atomic mass and nucleon number
Who created the periodic table - and in what year?
A Russian scientist called Dmitri Mendeleev in 1869
How many elements are there?
There are currently 118 different elements
94 elements occur naturaly. Where were the others created?
The elements that do not occur naturally have been synthesised in laboratories.
What is a column and row in the periodic table?
Each column in the Periodic Table is called a group and each row is called a period.
What does the period show in the periodic table?
The electron shell that’s being filled.
What does the group show in the periodic table?
The number of electrons in the valence shell is equal to the group number. Note, if the group number has two numbers (17), we take the last number (7).
What is a metalloid? Provide an example.
Metalloids have some properties of metals and some properties of non-metals. Arsenic is an example of one of these elements. It is shiny like a metal, but forms acidic oxides like a non-metal.
What propeties do elements in the same group on the periodic table have in common?
Elements in the same group have the same number of electrons in their outer shell. As it is the number of electrons in the outer shell that determines how an element reacts, this means that elements in the same group react in a similar way.
What is an Isotope?
Atoms of the same element so they have the same proton number but with different numbers of neutrons (nucleon number).
What is the relative mass of a proton?
1
What is the relative mass of a neutron?
1
What is the relative mass of an electron?
It’s so little, it’s negligable. Therefore, it’s viewed as 0.
How does being an isotope of an element affect chemical reactions?
It doesn’t.
As the atomic numbers are the same, isotopes of an element have the same number of electrons and the same electronic configuration. Therefore, they have the same chemical propeties and reactions, as neutrons don’t affect chemical reactions.
How would you write the isotope Carbon, with 12 neutrons?
carbon - 12
What is nuclear notation?
A method of displaying the key data of an element and its isotopes. The symbol for the element is preceded by the proton number (bottom) and nucleon number (top). To create the nuclear notation, the mass number is placed at the upper-left (superscript) of the chemical symbol and the atomic number is placed at the lower-left (subscript) of the symbol.
What is a transition metal?
Any of various metallic elements (such as chromium, iron, and nickel) that have valence electrons in two shells instead of only one.
Or
Elements in groups 3-12 of the table, forming the d-block.
What causes an element to conduct electricity?
They have a high number of free electrons moving through them.
