Answer:
Explanation:
We are asked to find how many moles are in 4.8 × 10²³ fluorine atoms. We convert atoms to moles using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of fluorine.
We will convert using dimensional analysis and set up a ratio using Avogadro's Number.
We are converting 4.8 × 10²³ fluorine atoms to moles, so we multiply the ratio by this number.
Flip the ratio so the units of atoms of fluorine cancel each other out.
Condense into 1 fraction.
Divide.
The original measurement of atoms has 2 significant figures, so our answer must have the same. For the number we found, that is the hundredths place. The 7 in the thousandths tells us to round the 9 in the hundredths place up to a 0. Then, we also have to round the 7 in the tenths place up to an 8.
4.8 × 10²³ fluorine atoms are equal to <u>0.80 moles of fluorine.</u>
Answer:
The correct answer is b.
Explanation:
The quantum number n specifies the energetic level of the orbital, the first level being the one with the least energy. As n increases, the probability of finding the electron near the nucleus decreases and the orbital energy increases.
In the case of atoms with more than one electron, the quantum number l also determines the sublevel of energy in which an orbital is found, within a certain energy level. The value of l is designated by the letters s, p, d, and f.
Have a nice day!
It was by far "warm and wet growing seasons" that was the most important factor in terms of the South's economic development. Cotton and tobacco were the biggest exports.
Explanation:
These crops created tons of cash, had massive markets round the world, however required a stable and enormous hands to grow and harvest them.The yank South is understood for its long, hot summers, and wealthy soils in stream valleys creating it a perfect location for growing cotton. the various southern seaports and riverside docks allowed shipping cotton to remote destinations. By 1860, Southern plantations equipped seventy fifth of the world's cotton, with shipments from Houston, city, Charleston, Mobile, Savannah, and some different ports. The unquenchable European demand for cotton was a results of the commercial Revolution that created the machinery and factories to method raw cotton into vesture that was higher and cheaper than hand-made product.
Answer:
2.04 x 10²⁴ molecules
Explanation:
Given parameters:
Mass of Be(OH)₂ = 145.5g
To calculate the number of molecules in this mass of Be(OH)₂ we follow the following steps:
>> Calculate the number of moles first using the formula below:
Number of moles = mass/molarmass
Since we have been given the mass, let us derive the molar mass of Be(OH)₂
Atomic mass of Be = 9g
O = 16g
H = 1g
Molar Mass = 9 + 2(16 + 1)
= 9 + 34
= 43g/mol
Number of moles = 145.5/43 = 3.38mol
>>> We know that a mole is the amount of substance that contains Avogadro’s number of particles. The particles can be atoms, molecules, particles etc. Therefore we use the expression below to determine the number of molecules in 3.38mol of Be(OH)₂:
Number of
molecules= number of moles x 6.02 x 10²³
Number of molecules= 3.38 x 6.02 x 10²³
= 20.37 x 10²³ molecules
= 2.04 x 10²⁴ molecules
Answer:
True
Explanation:
The majority of the reactions happened with a flow of heat. When there's no heat, the reaction is adiabatic.
For no adiabatic reactions, the heat can be released (evolution) by the system, so the reaction will be exothermic, or absorbed by the system (absorption), then the reaction is called endothermic.
