CHEMICAL SYMBOLS MEANING
what does H mean on the periodic tabe
HYDROGEN
What are the horizontal rows and vertical columns of the periodic table called?
Rows are periods; columns are groups or families
What is the periodic law?
THE PROPERTIES OF THE ELEMENTS REPEAT PERIODICALLY
WHAT DOES H E MEAN ON PERIODIC TABLE
HELIUM
Why are the noble gases (Group 18) extremely unreactive compared to other elements?
They have a full outer valence electron shell, making them highly stable
What is a period? How many are there in the periodic table?
A HORIZONTAL ROW IN THE PERIODIC TABLE; 7
WHAT DOES LI MEAN ON THE PERIODIC TABLE
LITHIUM
What is the difference between an element's atomic number and its atomic mass?
Atomic number is the number of protons; atomic mass is the total weighted mass of protons and neutrons
Which of the following pairs of elements belong to the same period?
a. Na and Cl b. Na and Li c. Na and Cu d. Na and Ne
Na and Cl
WHAT DOES B E MEAN ON THE PERIODIC TABLE
BERYLLIUM
Which family contains the most reactive metals, and which contains the most reactive non-metals?
Alkali metals/Group 1 and Halogens/Group 17
Which of the following pairs of elements belong to the same group?
a. H and He b. Li and Be c. C and Pb d. Ga and Ge
C and Pb
WHAT DOES B MEAN ON THE PERIODIC TABLE
BORON
What happens to atomic radius (size) as you move from left to right across a single period, and why?
It decreases because an increasing nuclear charge pulls the electrons closer to the nucleus
How does an element’s period number relate to the number of the energy level of its valence electrons?
PERIOD NUMBER = ENERGY LEVEL OF VALENCE ELECTRONS