<h2>
Hello!</h2>
The answer is: Charle's Law.
<h2>
Why?</h2>
The law that states that the volume and absolute temperature of a fixed quantity of gas (ideal gas) are proportional under constant pressure is the Charle's Law, also known as the law of volumes.
The law describes how a gas kept under constant pressure tends to expand when the temperature increases and it's described by the following equation:

Where,

Also, to describe the relationship between two differents volumes at different temperatures, we have:

Where,

Have a nice day!
Answer : The metal used was iron (the specific heat capacity is
).
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of unknown metal = ?
= specific heat of water = 
= mass of unknown metal = 150 g
= mass of water = 200 g
= final temperature of water = 
= initial temperature of unknown metal = 
= initial temperature of water = 
Now put all the given values in the above formula, we get


Form the value of specific heat of unknown metal, we conclude that the metal used in this was iron (Fe).
Therefore, the metal used was iron (the specific heat capacity is
).
Answer:
How to prepare Magnesium Carbonate:
Explanation:
Magnesium carbonate can be prepared in laboratory by reaction between any soluble magnesium salt and sodium bicarbonate: MgCl2(aq) + 2NaHCO3(aq) → MgCO3(s) + 2NaCl(aq) + H2O(l) + CO2(g)
In an atom, the number of neutrons determines most specifically the isotopes of an element.
<h2>Further Explanation</h2><h3>An atom </h3>
- An atom is defined as the smallest particle of an element that can take part in a chemical reaction.
- Atoms are made of energy shells and the inner nucleus.
- It is also made up of subatomic particles, protons and neutrons.
<h3>Neutrons </h3>
- They are sub-atomic particles in an atom that are found in the nucleus of an atom. They have a zero charge or no charge.
- Neutrons are slightly heavier than protons.
- The number of protons and neutrons in a nucleus of an atom results to the atomic mass number of an atom. Like protons they only take part in nuclear reactions.
<h3>Protons</h3>
- Protons are subatomic particles that are found in the nucleus of an atom. They are positively charged. with a charge of +1.
- The number of protons differ from one element to another and thus used as the atomic number of an individual element.
- The nucleus of an atom is positively charged due to the positive charge of the protons.
- Additionally, protons do not take part in chemical reactions but in nuclear reactions.
<h3>Electrons </h3>
- They are found orbiting the nucleus on energy shells based on Clouds’ theory. Electrons are negatively charged each with a charge of -1.
- The number of electrons and protons in a neutral atom are equal. Additionally they have the least mass of the three sub-atomic particles.
- Electrons are the only sub-atomic particles that take part in chemical reactions.
<h3>Isotopes </h3>
- Isotopes are atoms of the same element that have the same mass number but different atomic number.
<h3>Mass number;</h3>
- Mass number is the sum of the number of protons and neutrons in the nucleus of an atom of an element.
Keywords: Atom, sub-atomic particles, electrons, protons, neutrons, isotopes
<h3>Learn more about:</h3>
Level: High school
Subject: Chemistry
Topic: Atomic structure
Answer:
3 m/s
Explanation:
▲
usando la fórmula velocidad = frecuencia multiplicada por la longitud de onda.
v = (1.5)(2)
v= 3 m/s