Answer:
D.
Explanation:
The rock that is left behind is there because it has resisted the forces of erosion.
Soluble means it can be dissolved
Insoluble means it can't be dissolved
Answer:
Option C = same period.
Explanation:
All these elements belongs to second period of periodic table. This period consist of eight elements lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine and neon.
Electronic configuration of lithium:
Li₃ = [He] 2s¹
Electronic configuration of beryllium:
Be₄ = [He] 2s²
Electronic configuration of boron:
B₅ = [He] 2s² 2p¹
Electronic configuration of carbon:
C₆ = [He] 2s² 2p²
Electronic configuration of nitrogen:
N₇ = [He] 2s² 2p³
Electronic configuration of oxygen:
O₈ = [He] 2s² 2p⁴
Electronic configuration of fluorine:
F₉ = [He] 2s² 2p⁵
Electronic configuration of neon:
Ne₁₀ = [He] 2s² 2p⁶
All these elements present in same period having same electronic shell.
However their families, valance electrons and group are different. Boron have three valance electrons and belongs to group 3A. Carbon belongs to group 4A and have 4 valance electrons. Nitrogen belongs to group 5A and have five valance electrons. Oxygen belongs to group 6A and have six valance electrons. Fluorine belongs to group 7A and have seven valance electrons.
Of all the elements, fluorine is the most electronegative and reactive. Fluorine is a diatomic, pale yellow, extremely corrosive, combustible gas with a strong smell. The lightest halogen is it. It produces oxygen and the incredibly corrosive hydrofluoric acid when it combines strongly with water.
<h3>The properties of the oxide and the fluoride?</h3>
- 1. A mixture of oxygen fluorides with an atomic ratio OF in the range of 1.1-2.04 is generated when fluorine and oxygen mixes are easily circulated through a silent electric discharge.
- Depending on where you reside in the UK, fluoride is a naturally occurring mineral that is present in water in variable concentrations. It is added to many types of toothpaste and, in some locations, the water supply through a procedure known as fluoridation because it can aid in the prevention of tooth decay.
- Fluoride stops tooth decay by strengthening the enamel's resistance to acid attack. They also quicken the process of good minerals accumulating in the enamel, further delaying the onset of deterioration. Studies also suggest that fluoride may occasionally be able to stop tooth decay that has already begun.
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