Answer:
Option B is correct.
4
Explanation:
We know that an atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example, if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
In given problem we are given with 2 neutrons of helium. We know that the atomic number of He is 2. Thus Mass number of He is,
Number of neutrons + number of proton
2 + 2 = 4
Thus, option B is correct.
Answer: I italicize for checking
- <em>Rocks are preserved through the process.</em>
- <em>Rocks change from one type to another.</em>
- <em>Different rock groups are interrelated.</em>
- Rocks change from one type to another in a specific order.
- <em>Environmental conditions influence a change in rock type.</em>
Explanation:
Rocks are preserved, as in you can't destroy them completely, but no, they don't <em>stay </em>the same they change.
Answer:
bromine (Br)
Explanation: Iron enters into a reaction with substances of different classes, and interacts with oxygen, carbon, phosphorus, halogens (bromine, iodine, fluorine and chlorine), and also nitrogen. These are not all the reactions of iron – this metal reacts with many elements.
Answer:
c. 2NH₃ + 2H₂O + Cu²⁺ → Cu(OH)₂(s) + 2NH₄⁺
Explanation:
A net ionic equation is a chemical equation that list only the species that are involved in the reaction.
The reaction of ammonia with copper(II) sulfate CuSO₄ in water is:
2NH₃ + 2H₂O + CuSO₄ → Cu(OH)₂(s) + 2NH₄⁺ + SO₄²⁻
In an ionic equation, salts are written as ions, that means CuSO₄ must be written as Cu²⁺ + SO₄²⁻. That is:
2NH₃ + 2H₂O + Cu²⁺ +<u> SO₄²⁻</u> → Cu(OH)₂(s) + 2NH₄⁺ + <u>SO₄²⁻</u>
As in a net ionic equation you must list only the species involved in the reaction (The underlined species don't react), the net ionic equation is:
<em>c</em>. <em>2NH₃ + 2H₂O + Cu²⁺ → Cu(OH)₂(s) + 2NH₄⁺</em>
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I hope it helps!
