When two magnets are brought near each other, like poles repel; opposite poles attract. When a magnet is brought near a piece of iron, the iron also gets attracted to the magnet, and it acquires the same ability to attract other pieces of iron.
Answer:
A) 20
B) 40
C) Ca
D) 10
E) 9
F) F
Explanation:
The MASS NUMBER is the number of protons + the number of neutrons.
The ATOMIC NUMBER is the number of protons.
You can take the MASS NUMBER - ATOMIC NUMBER = NUMBER OF NEUTRONS.
Each element is unique and distinguished by the NUMBER OF PROTONS = ATOMIC NUMBER, ie...the number of protons in its nucleus. You can find the element's name and symbol on the Periodic Table.
