A) Cu
Cu + 2HCl --> CuCl2 + H2(g)
Products predicted: Copper(II) choloride and hydrogen gas
B) Mg
Mg + 2HCl --> MgCl2 + H2
Products predicted: magnesium chloride + hygrogen gas
C) Fe
Fe +2 HCl -> FeCl2 + H2, or
2Fe +6 HCl -> 2FeCl3 + 3H2
Products predicted: Iron(II) chloride, iron (III) chloride and hydrogen gas.
Steps of a scientific investigation include identifying a research question or problem, forming a hypothesis, gathering evidence, analyzing evidence, deciding whether the evidence supports the hypothesis, drawing conclusions, and communicating the results.
I believe it’s 2? Because it’s saying read the temperature. Which is basically saying look at what state the water is in. Ex: hot or cold
1.51 x 10²⁵atoms
Explanation:
Given parameters:
Mass of Na = 578g
Unknown:
Number of atoms = ?
Solution:
To find the number of atoms, we must first find the number of moles the given mass contains.
Number of moles = 
molar mass of Na = 23g
Number of moles =
= 25.13moles
1 mole of a substance = 6.02 x 10²³atoms
25.13 mole of Na = 25.13 x 6.02 x 10²³atoms
This gives 1.51 x 10²⁵atoms of Na
Learn more:
Avogadro's constant brainly.com/question/2746374
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Hello!</h2>
The answer is: Charle's Law.
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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!