Q111 of 147 Page 8

An atom changes to a charged particle called ion if it loses or gains electrons. The charge on an ion is the charge on electrons plus charge on protons. Now, write the missing information in the table given below:

We know that, Charge on an ion is basically charge on electron plus charge on proton.


Symbolically, Charge on an ion = Charge on electron + Charge on proton


For Hydroxide:


Proton charge = +9


Electron charge = p (let)


Ion charge = -1


So, Ion charge = electron charge + proton charge


⇒ -1 = p + 9


⇒ p = -1 – 9


⇒ p = -10


For Sodium ion:


Proton charge = +11


Electron charge = q (let)


Ion charge = +1


So, Ion charge = electron charge + proton charge


⇒ 1 = q + 11


⇒ q = 1 – 11


⇒ q = -10


For Aluminium ion:


Proton charge = +13


Electron charge = -10


Ion charge = r (let)


So, Ion charge = electron charge + proton charge


⇒ r = -10 + 13


⇒ r = 3


For Oxide ion:


Proton charge = +8


Electron charge = -10


Ion charge = s (let)


So, Ion charge = electron charge + proton charge


⇒ s = -10 + 8


⇒ s = -2



More from this chapter

All 147 →
109

Observe the following patterns and fill in the blanks to make the statements true:

7 × 4 = 28


7 × 3 = _______ = 28 – 7


7 × 2 = __ __ = _______– 7


7 × 1 = 7 = _______ – 7


7 × 0 = ______ = ______ –_______


7 × – 1 = –7 = ______ – _______


7 × – 2 = _____ = _____ – ______


7 × – 3 ______ = ______ – _______

 110

Science Application: An atom consists of charged particles called electrons and protons. Each proton has a charge of +1 and each electron has a charge of –1. Remember number of electrons is equal to number of protons, while answering these questions:

(a) What is the charge on an atom?


(b) What will be the charge on an atom if it loses an electron?


(c) What will be the charge on an atom if it gains an electron?

 112

Social Studies Application: Remembering that 1AD came immediately after 1BC, while solving these problems take 1BC as –1 and 1AD as +1.

A. The Greeco-Roman era, when Greece and Rome ruled Egypt started in the year 330 BC and ended in the year 395 AD. How long did this era last?


B. Bhaskaracharya was born in the year 1114 AD and died in the year 1185 AD. What was his age when he died?


C. Turks ruled Egypt in the year 1517 AD and Queen Nefertis ruled Egypt about 2900 years before the Turks ruled. In what year did she rule?


D. Greek mathematician Archimedes lived between 287 BC and 212 BC and Aristotle lived between 380 BC and 322 BC. Who lived during an earlier period?

 113

The table shows the lowest recorded temperatures for each continent. Write the continents in order from the lowest recorded temperature to the highest recorded temperature.