Lesson 4: Element and periodic table Flashcards
1
Q
What is an element?
A
An element contains only one kind of atom
For example, sodium is made of sodium atom only, so it’s an element
2
Q
How many elements have been found in the Earth and atmosphere?
A
Around 90
3
Q
What is the nucleon number?
A
The mass number (protons + neutrons)
4
Q
What is the atomic number?
A
Number of protons
5
Q
where do we find the mass number and atomic number of an element?
A
We look in the periodic table!
6
Q
What are groups?
A
Vertical columns are called groups, they’re numbered from 1-8
7
Q
What are periods?
A
Horizontal rows are called periods, and numbered from 1-7
