Answer:
Samira's model is incorrect because not all atoms are accounted for
Explanation:
The image of Samira's model has been attached to this answer to enhance the explanation.
What is depicted in that model is rightly regarded as a chemical change. In a chemical change atoms of substances are rearranged as new substances are formed.
However, all atoms in the products must also be found in at least one of the reactants. In this case we have an atom in one of the products that is not accounted for. Hence the model is incorrect.
Explanation:im not really sure about this one but i think it is either c or b
ANSWER:C im pretty sure.sorry if wrong
Blue to red is acidic, red to blue is basic and no change is neutral.
<h2>
Answer:HCl</h2>
Explanation:

For 



For 



The reaction between
and
is
→
So,one mole of
requires one mole of 
moles of
requires
moles of 
But there are only
moles of
available.
will be consumed first.
So,
is the limiting reagent.
Answer:
A
Explanation:
Polypeptides such as proline and glycine are capable of making a sharp turn called a reverse turn due to the suitability and flexibility of their cyclic structure