Boys:
Your voice will get deeper (this is called voice breaking)
Hair around the base of your penis / scrotum - this will be one of the very early signs
Underarm hair - A few people however do not grow it
Penis enlargement
Rapid height growth
Changes in mental outlook
Girls:
Breasts develop
Menstruations will start
Underarm hair
Hair round the genital area
Rapid height growth
Changes in mental outlook
Capricious, fickle.
You would call this person a child. By the time a child reaches puberty, he or she knows.
The perspective about puberty changes from person to person. Some boys don't like the growth of facial hair. Also the mood swings are pretty bad.
Yes
When it reaches puberty
Testosterone is a male hormone which is produced by the testes once a boy reaches puberty. It triggers the changes in a boy's body which turn him from a boy to a man.
Puberty
400,000
This changes from person to person. That is why some people's voice changes a lot while other people's voice remains some what same.
A person goes through a lot of changes, both physical and behavioural. relaxation helps the person being calm and reduces the behavioural changes.
At the end of puberty, boys will have a deep voice, notice their emotions are controllable, and become less easily aroused (fewer involuntary erections), and other major physical changes such as hair growth.
Adult age is when a Muslim reaches Puberty