The answer is 1.02 × 10²⁵ atoms.
1. Calculate molar mass (Mr) of P2O5 which is the sum of atomic masses (Ar) of its elements:
Ar(P) = 31 g/mol
Ar(O) = 16
Mr(P2O5) = 2 * Ar(P) + 5 * Ar(O) = 2 * 31 + 5 * 16 = 62 + 80 = 142 g/mol
2. Calculate number of moles (n) which is the quotient of a sample mass (m) and the molar mass (Mr):
n = m/Mr
m = 0.240 g
Mr = 142 g/mol
n = 0.240 / 142 = 0.0017 mol
3. Avogadro's number is the number of units atoms in 1 mole of substance:
<span>6.023 × 10²³ atoms per 1 mol
x atoms are per 0.0017 mol
</span>6.023 × 10²³ atoms : 1 mol = x atoms : 0.0017 mol
x = 6.023 × 10²³ atoms * 0.0017 mol : 1 mol
x = 0.0102 × 10²³ = 1.02 × 10² × 10²³ = 1.02 × 10²⁵ atoms
Since chlorine is one of the 7 diatomic elements we know that chlorine appears as Cl₂ gas naturally. That means that the molar mass of a chlorine gas is 70.9g/mol. That being said, first you need to find the number of moles of chlorine gas that are present in a 35.5g sample. To do this divide 35.5g by the molar mass of chlorine gas (70.9g/mol) to get 0.501mol of chlorine. Then you have to multiply 0.501mol by 6.02×10²³ to get the number of chlorine gas molecules. Therefore 3.01×10²³ molecules of chlorine gas are present in a 35.5g sample.
I hope that helps. Let me know in the comments if anything is unclear.
Answer:
2.01
Explanation:
First, let's convert grams to moles
(Na) 22.99 + (F) 18.998 = 41.988
Every mole of NaF is 41.988 grams
21/41.988 = 0.500143 moles of NaF
For every Cr+3, we will need 2 NaF, so Cr+3 will be half of NaF
0.500143/2 = 0.250071
molarity = moles/liters
0.250071/0.125 = 2.0057 M
Controls senses and most body functions .
Carries message and information between the brain & body
Explanation:
The nervous system helps to control senses, body functions, carries message and information between brain and the body. It consists of the brain, spinal cord and the nerves.
- Using series of electrical nerve impulses, the nervous system controls the body administration.
- The brain, spinal cord and nerves directs communications between different parts of the body system.
- It is divided into two broad categories, the central nervous system which consists of the brain and spinal cord and the peripheral nervous system which is made up the nerves.
Learn more:
neuron brainly.com/question/4662759
nervous system brainly.com/question/8701152
#learnwithBrainly
I believe the answer is D because warm water generally has more nutrients than cold water.
It does not improve the nutrients so it isn't B or C.
Hope this helps!
