Answer:
I think its iron(II) oxide
Explanation:
The substance is black but when it's mixed with water it turns green solution so when mixed with sodium Hydroxide it turns green
They react to form salt ZnCl + hydrogen gas
Answer: The number 4 indicates 4 electrons.
Explanation: We are given an electronic configuration, which is:

Here,
- The letters denote the sub-shells of an element.
- The numbers written before the letters which are 1, 2 and 2 represents the Principle Quantum Number and these represents the energy level of the sub-shells.
- The number which are written in the superscripts which are 2, 2 and 4 denotes the electrons which are present in the sub-shell.
Hence, 4 indicates 4 electrons present in 2p sub-shell.
The flotation process used in metallurgy involves the separation of gangue from ore.
<h3>How does the flotation process work?</h3>
The various wettability qualities of a material's surface are the foundation of flotation operations. The basic principles of flotation are quite similar to those of a sink and float process, where the materials' relative densities to the medium in which they are deposited determine the basis of the separation.
<h3>What is the process of separating minerals from gangue known as?</h3>
Mineral processing, mineral dressing, or ore dressing are all terms for the process of separating minerals from gangue. It is an important and frequently necessary part of mining. Depending on the type of minerals used, the process may be difficult.
Learn more about minerals here:-
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