The "sea of instability" refers to a region of elements on the periodic table that are highly unstable. These elements have extremely short half-lives that may be measured in micro- or nanoseconds. (A nanosecond is the time it takes for light to travel one foot.) This region of unstable elements surrounds the island of stability.
Answer:
last one is the correct and most suitable option.
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Answer:
The hydrogen atom has just one electron, but many spectral lines. However it contains many shells and the movement of that electron from one shell to another causes the release of energy and also an emission of photons.
A spectral line are dark or bright lines formed within a specific frequency range which differ from other frequencies.Because of the difference of energy for the various shells, it produces different wavelengths and this is the reason for the many spectral line for hydrogen.
Explanation:
A ____Chemical Reaction_______________________ is a well defined example of a chemical change. A chemical ___ _____chemical equation___________________ can be used to show the changes that occur in a chemical reaction. In a chemical reaction, the substance on the left side of the arrow are the starting substance. These substances are called ___Reactants________________________. The substances on the right side of the arrow are the substances that result from the reaction. These substances are called ____________Products_______________. The arrow is read as either produces or ______yields_____________________. According to the law of conservation of __________mass_________________, atoms are neither lost nor gained during a chemical reaction. This law is illustrated when a chemical equation is ________Balanced___________. When this is done, there will be the same number of ___________atoms________________ of each kind on both sides of the equation. In a chemical equation, the numbers that are placed in front of the symbols and the formulas are called ______________coefficients_____________. They are necessary to keep the ___________________________ of atoms in balance. There are several rules for balancing an equation. First, write the correct ____________(not so sure)_____________ for each reactant and product. Next, choose the coefficients that make the number of atoms of each _______elements(not so sure)________________ on each side of the equation equal. The correctly written formula should not be changed. If you change the formula of a substance, the equation is no longer ___________correct_____________. Changing a formula will indicate a ________Substance___________________ different than the one intended. To balance the equation Mg + O2 à MgO, first choose coefficients to make the number of atoms of each element on each side of the equation equal. You would need to place a coefficient of _________two___________
