Answer is: because they were using simple chemical reactions to transform elements, but that is possible only with nuclear reactions, which in that time were not possible to conduct.
Nuclear reactions can produce new elements, because number of protons and neutrons is changed, lead and gold have different atomic and mass numbers.
The electrons of an atom participates in a chemical reaction, chemical reactions involve the rearrangement of electrons, because there is transfer, loss, gain and sharing of electrons in chemical reactions, new elements are not formed.
Answer choice A, B, and C is right about the valence electrons. For answer choice D and E, Would in it be a more of an element kind of choice. whether the element is closer to the left side of the periodic table or not determines the high and low energy.
It's a compound because it's formed from an ionic bond between calcium and carbon so it's an ionic compound
Answer:
pOH = 11.5
[H⁺] = 0.003 M
[OH⁻] = 3 × 10⁻¹² M
Explanation:
The computation is shown below:
Given that
pH = 2.5
Based on the above information
We know that
pH + pOH = 14 ⇒ pOH = 14 - pH
pOH = 14 - 2.5
pOH = 11.5
[H⁺] = 10^(-pH) = 10^(-2.5)
[H⁺] = 0.003 M
[OH⁻] = 10^(-pOH)
= 10^(-11.5)
= 3 × 10⁻¹² M
[OH⁻] = 3 × 10⁻¹² M
Hence, the above represents the answer
