Answer:
The safety button doesn't click before the jar has been opened because it shows a sign of freshness. Once you have opened it there is no way to make it click again.
If bacteria gets stored in the jar they will produce gas. If the button does not pop or click after opened that is a sign that it may not be so safe to eat. Clicking shows that there is still vacuum to the jar.
Explanation:
Connective tissue is one of the four different types of tissues. It consists of cells suspended in a matrix, and consist of fibres running through it. It’s main job is to connect internal tissues. They also support and protect internal organs. Examples include cartilage, blood, lymph and adipose tissue.
Answer:
The molecular formula of estradiol is:
.
Explanation:
Molar mass of of estradiol = M= 272.37 g/mol
Let the molecular formula of estradiol be 
Percentage of an element in a compound:

Percentage of carbon in estradiol :

x = 18.0
Percentage of hydrogen in estradiol :

y = 24.2 ≈ 24
Percentage of oxygen in estradiol :

z = 2
The molecular formula of estradiol is: 
The answer is beryllium-10
Answer:
b-Mg
d-Ca
Explanation:
all the group two metals have oxidation of 2