00:01
The question has given assertion which says the main cause of tooth decay is an increase in the ph of the saliva after meal.
00:38
And for this assertion, they have given the reason that saliva becomes more acidic after meal.
00:55
So first we will understand what is the process then we will come to this assumption and reasoning.
01:08
The ph of the saliva after meal is 5 .8.
01:23
So after the meal, but usually the ph of the saliva is ph after saliva is in between 6 .5 to 7 .5.
01:39
So if you see the ph scale, this knowledge we have, from 0 to 7, whatever value will come, that we call it as acidic.
01:49
From 7 to 14, whatever comes, that is called as basic.
01:55
And at 7, it is neutral in nature.
01:59
So this, the second reason, whatever is the saliva becomes more acidic...