The number of valence electrons that a neutral atom of aluminum has is 3 valence electrons.
Valence electrons are those electrons in the outermost parts of elements that can be combined or loned to other elements during chemical reactions. Aluminum has three electrons in the valence shell.
The total number of electrons that aluminum has is 13 and the 3P1 shell has three electrons. So, this is the number of valence electrons.
Learn more about valence electrons here:
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Answer:
Aluminum has 13 electrons in a neutral atom. The 1S2, 2S2 and 2P6 shells are full, and so is the 3S2. The 3P1 shell has one electron in it (in Al's neutral atom) and that gives aluminum one lone valence electron and two "semi-valence" electrons which can be loaned out.
Explanation:
Explanation:
As we all know that like disolves in like solvent.
Here both water and Ethanol are polar. Hence Ethanol soluble in water.
Moreover, both forms intermolecular hydrogen bonds. It enhances the solubility of ethanol.
Both water and Ethanol are called as associate liquids. Hence solubility is more.
Alcohols have higher boiling point than other hydrocarbons due to their polarity and from the fact that they form very strong intermolecular hydrogen bonding. This is due to the large difference in their electronegativity that forms between the oxygen and the hydrogen atom.
a. Número de protones _______________
b. Número de electrones _______________
c. Número de neutrones _______________
b. 56.00 s ( a time measured by a stopwatch)
c. 4 choices ( the number of choices in this list)
d. 3 lbs ( the weight of an object measured on a scale )
Answer: a. 2.54 cm ( the number of centimeters in exactly 1 in) and c. 4 choices ( the number of choices in this list)
Justification:
1) a. 2.54 cm ( the number of centimeters in exactly 1 in)
Although the exact length of one inch has varied in the past, currently the inch is defined as exactly 2.54 cm, so this is an exact number.
b. 56.00 s ( a time measured by a stopwatch)
The time measured by a stopwatch is not an exact number. The number is limited by the precision of the instrument (the stopwatch) and it migh have been 56.004 instead of 56.00, and the stopwatch cannot shoe that. So, this is not an exact number.
c. 4 choices ( the number of choices in this list)
This is, indeed an exact number. It is 4, not 4.1, nor 3.9, nor any other number.
d. 3 lbs ( the weight of an object measured on a scale )
As reasoned with the stopwatch, this measure, 3 lbs, is subject to the precision of the scale. It is not an exact number. It could be other number close to 3: 2.99 for example.
These are exact numbers: c. 4 choices ( the number of choices in this list) and d. 3 lbs ( the weight of an object measured on a scale )
The exact number is a value that is known with complete certainty. Examples are counted numbers of objects or certain unit conversions such as exactly 3 feet in 1 yard. Another example is, a dozen is defined as 12 objects, and a pound is defined as 16 ounces.
Fraction an exact number is a fraction takes two integers and places them in a ratio, for example 3/4 or 10/15. A decimal can express the same numerical quantity, but it does so with a single number (like 0.75 or 0.66). So, the fraction makes the relationship among numbers clear in the way it is written.
While a decimal can express the same numerical quantity, but it does so with a single number (like 0.75 or 0.66).
a. 2.54 cm ( the number of centimeters in exactly 1 in) is decimal
b. 56.00 s ( a time measured by a stopwatch) is not exact numbers
c. 4 choices ( the number of choices in this list) is exact numbers
d. 3 lbs ( the weight of an object measured on a scale ) is exact numbers
Grade: 9
Subject: chemistry
Chapter: exact number
Keywords: exact number
Answer:
selenium, Se
Explanation:
Selenium is the only element that has a melting point below 525 K. Therefore, it would be the only element that would be liquid at that temperature.
At 525 K, only bismuth would be in the liquid phase as its melting point is 544.7 K and boiling point is 1837 K, while all other elements would be in the solid state.
The question asks about the phase of different elements at a specific temperature of 525 K. To answer the question, we need to know the melting and boiling points of these elements: platinum (Pt), selenium (Se), bismuth (Bi), copper (Cu), and calcium (Ca).
At 525 K, bismuth (Bi) would be in the liquid state as its melting point is 544.7 K and boiling point is 1837 K. All other elements mentioned have melting points and boiling points higher than 525 K, so they would be in the solid state.
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