Answer:
#1 is an organism
#2 is cell
#4 - Digestive System gets nutrients (good) from food and hands it over to the blood and Circulatory System then carries those nutrients where they need to go
Answer: There are 0.006 moles of acid in the flask.
Explanation:
Given:
= 21.35 mL,
= 0.150 M
= 25.0 mL,
= ?
Formula used to calculate molarity of
is as follows.

Substitute the values into above formula as follows.

As molarity is the number of moles of a substance present in a liter of solution.
Total volume of solution = 
= 21.35 mL + 25.0 mL
= 46.36 mL (1 mL = 0.001 L)
= 0.04636 L
Therefore, moles of acid required are calculated as follows.

Thus, we can conclude that there are 0.006 moles of acid in the flask.
Hydrogen and Helium are the first 2 elements
Answer:
A.
A chemical reaction was producing a new substance.
Explanation:
Equation of the reaction
NaOH + HCl --> NaCl + H2O
Heat of neutralization is the amount of heat evolved when one mole of acid reacts with one mole of an alkaline to form one mole of water.
When a neutralisation reaction is carried out, there is an exothermic change; energy released into the surroundings therefore since heat is given out which is what is felt.