Answer:
nucleus
Explanation:
The nucleus holds all the other things, keeping them safe and confined.
<u>Answer:</u>
<em>The amount of energy needed when water at 72 degrees c freezes completely at 0 degrees c is 
Joules</em>
<em></em>
<u>Explanation:</u>
where
= Final T - Initial T
=30125J
Q is the heat energy in Joules
c is the specific heat capacity (for water 1.0 cal/(g℃)) or 4.184 J/(g℃)
m is the mass of water
mass of water is assumed as 100 g (since not mentioned)
is the heat energy required for the phase change
=mass × heat of fusion
Total heat = 
Total Heat = 30123J + 33600J
= 63725 J
= Joules is the answer
Answer:
a) the system is closed
b) the system is open
Explanation:
a) the system can be characterised as closed system. If we define the boundaries of this system as an envelope that contains the bathtub, then there will not be any mass transfer to the environment through the boundary → then the system is closed ( the mass of the system remains constant)
b) on the other hand , taking the same system as in the first case, if the hot water is continually added to the tub , then there is water flow through the boundary (from the environment to the system) → then the system is open ( the mass of the system can be altered)
1. Iron fillings are magnetic, so use a magnet to pull the iron fillings out of the mix.
2. Then you can put the salt and sand mixture into water, since salt is soluble, and the salt will dissolve, leaving you with sand.
Balanced chemical equation for the given reaction is Fe₂(CO₃)₃ + 6Cs → 3Cs₂CO₃ + 2Fe.
<h3>What is balanced equation?</h3>
Balanced chemical equations are those equations in which all entities are present in equal amount on reactant side as well as on product side.
Given balanced chemical reaction is:
Fe₂(CO₃)₃ + 6Cs → 3Cs₂CO₃ + 2Fe
Above given equation is a balanced chemical equation where all atoms of reactant as well as of products are present in same amount.
Hence, required balanced equation is Fe₂(CO₃)₃ + 6Cs → 3Cs₂CO₃ + 2Fe.
To know more about balanced chemical reaction, visit the below link:
brainly.com/question/26694427
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