When the water level of a stream or river exceeds its natural banks, it has reached its D. FLOOD STAGE
Flood stage is an established gauge height for a given location above which a rise in water surface level begins to create a hazard to live, property, or commerce. The issuance of flood warnings are the result of flood stage.
Answer:
The answer to your question is 3.69 x 10²¹ atoms of gold
Explanation:
Data
density = 19.32 g/cm³
dimensions = 2.5 cm x 2.5 cm x 0.1 mm
number of atoms of gold = x
Process
1.- Find the volume of the foil
Volume = length x height x width
Volume = 2.5 x 2.5 x 0.01
Volume = 0.0625 cm³
2.- Calculate the mass of the foil
Density = mass/volume
mass = density x volume
mass = 19.32 x 0.0625
mass = 1.208 g
3.- Calculate the number of atoms
Atomic number of Gold = 197 g
197 g -------------------- 6.023 x 10²³ atoms
1.208 g --------------- x
x = (1.208 x 6.023 x 10²³)/197
x = 3.69 x 10²¹ atoms of gold
A sample of silicon has an average atomic mass of 28.084amu. In the sample, there are three isotopic forms of silicon. About 92.22% of silicon atoms are 27.9769amu, which have the mass of 28Si; about 4.68% are 28.9764amu, which have the mass of 29Si, and the isotope 30Si, makes up the remaining 3.10%. Calculate the atomic mass of 30Si. Report your answer with three significant figures <u>The percentage abundance for </u><u>isotope </u><u>is 3.09 %.</u>
<h3>What is isotopes?</h3>
Isotopes are two or more atom types that share the same atomic number (number of protons in their nuclei), location in the periodic table, and chemical element but have distinct nucleon numbers (mass numbers) as a result of having a different number of neutrons in their nuclei. Although the chemical properties of each isotope of a given element are nearly identical, they differ in their atomic weights and physical characteristics.
The word "isotope" is derived from the Greek words "isos" and "topos," both of which imply "the same location." As a result, the name refers to the fact that various isotopes of a given element occupy the same spot on the periodic table. Scottish physician and author Margaret Todd first used it in a recommendation in 1913.
To learn more about isotopes from the given link:
brainly.com/question/364529
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<span>It is a chemical change. When milk turns sour for example in a warm room it is a chemical change. If it was a physical change you would be able to undo the souring of milk. Since you can't, it is not a physical change.</span>
~Deceptiøn
Answer:
B
Explanation:
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