A system is a part of the <em>physical</em> universe defined <em>arbitrarily</em> for observation purposes.
Boundaries are a part of the <em>physical</em> universe that are around the system.
In a scientific sense, a system is a part of the <em>physical</em> universe whose boundaries, that is, the limit between the system and its surroundings, are defined <em>arbitrarily</em> for observation purposes.
A system contains at least a model, represented in a phenomenological way, and it can be isolated (no mass nor energy interactions), closed (no mass interactions) or open.
The surroundings are a part of the <em>physical</em> universe that are around the system.
An example is a coffee-maker, where coffee-maker the system and air represents the surroundings, the coffee-maker receives energy from a heat source to warm up itself and releases part of such energy to the air.
We kindly invite to check this question on systems and surroundings: brainly.com/question/6044762
Answer : The balanced chemical reaction will be:

Explanation:
Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.
As we know that perbromic acid is considered a strong acid that means it will completely dissociate in water.
The balanced chemical reaction will be:

Answer:
The ratio between protons to electrons is not 1:1
Explanation:
A normal atom will be neutral in charge having 1 electron for each atom. An Atom that gains or looses an electron loses that perfect ratio. It is positive is electrons are loss and negative if electrons are gained.
Alleles are inside a gene and genes are made up by alleles. Also, a gene is DNA, so the allele is like piece of DNA inside a gene<span>.
Hope this helps:)
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C. The thermometer reads 100