Answer:
30, 50
Explanation:
Hello,
In this since an element's atomic number is equal to the number of protons in its atom, we can infer that selenium's atomic number is 30. Moreover, due to the fact the the neutrons are equal to the atomic mass minus the atomic number or the number of protons, by knowing the number of neutrons we compute the atomic as follows:

Thus, answer is 30, 50.
Best regards.
Answer:
Save the *minerals* used to extract metals.
Answer:
John Dalton
Explanation:
John Dalton in 1808 suggested that all matter consists of tiny particles called atoms and that the atoms of a specific element are identical.
He postulated the Dalton's atomic theory which has the following important parts;
- All matters consists of indivisible particles called atoms
- Atoms of the same element are similar and are different from atoms of other elements.
- Atoms can neither be created nor destroyed.
- Atoms combine in simple whole ratios to form compounds.
Answer: The ionization of pure water forms <u><em>hydroxide and hydronium ions.</em></u>
Explanation:
Ionization is a reaction in the pure water in which water breaks down into its constituting ions that hydronium ion and hydroxide ions.

One molecule of water looses its proton to form hydroxide ion and l=the lost protons get associated with another water molecule to form hydronium ion.
Female energy the answer is the first one