Answer:
True
Explanation:
Significant digits are numbers that helps to present the precision of measurements calculations.
Numbers that do not contribute to the precision of a reading should not be counted as significant.
There are rules of assigning significant numbers:
- Leading or trailing zeros are insignificant and should only be counted as a place holder.
- All non-zero digits are significant
- Zeroes between non-zero digits are significant.
- Leading zeros in a decimal are significant before the number.
- All the numbers in a scientific notation are significant.
Yes they will need to worry cause the chemicals could spread in the water making it explode and kill animals and it would be very bad
According to newtons law every action has a equal reaction therefore it will push back 200n aswell
Answer:- It is choice D. 
Explanations:- In general, a neutralization reaction is the reaction of an acid with base to form salt and water.
in first reaction the reaction is taking place between ammonia(a base) and hydrochloric acid(an acid) to form their salt(ammonium chloride). So, it is an acid-base neutralization reaction.
In second reaction, sodium hydroxide(a base) is reacting with acetic acid(an acid) to form their salt(sodium acetate) and water. So, it is an acid-base neutralization reaction.
In third reaction, Nitric acid is reacting with calcium hydroxide(a base) to form a salt(calcium nitrate) and water. So, it is an acid-base neutralization reaction.
In fourth reaction, sulfuruc acid is reacting a sodium chloride(a salt) to give a double replacement reaction. It is not an acid-base neutralization reaction as it's not taking place between an acid and base.
So, the correct choice is D. 
Xylene moles =\frac{17.12}{106.16×1000}=0.00016moles=
106.16×1000
17.12
=0.00016moles
Moles of CO_2 =\frac{56.77}{44.01×1000}=0.0013CO
2
=
44.01×1000
56.77
=0.0013
Moles of H_2O= =\frac{14.53}{18.02×1000}=0.0008H
2
O==
18.02×1000
14.53
=0.0008
Moles ratios
\frac{0.0013}{0.0008}=1.625
0.0008
0.0013
=1.625
\frac{0.0008}{0.0008}=1
0.0008
0.0008
=1
Hence molecular fomula
The empirical formula is C 4H 5.
The molecular formula C8H10