Answer:
Atomic number=No. of protons=No. of electrons in ground state(unchanged atom)
Atomic number=13=No. of protons
Atomic mass=no. of protons+no. of neutrons=13+14=27
For isotope no. of proton=13(same atomic number but different mass number are isotopes)
no. of electrons=13
no. of neutrons=14+2=16
Explanation:
hope it's help you
The molecular mass of pyrene is 204.4 g/mol.
From;
ΔT = Kb m i
Where;
- ΔT = boiling point elevation
- Kb = boiling point constant
- m = molality
- i = Van't Hoff factor
Since the compound is molecular; i = 1
The number of moles of pyrene = 4.04 g/MM
Where; MM = molar mass of pyrene
molality = number of moles of pyrene/mass of solvent in Kg
The mass of solvent = 10 g or 0.01 Kg
molality = 4.04 g/MM/0.01
ΔT = Boiling point of solution - Boiling point of pure solvent
ΔT = 85.1°C - 80.1°C
ΔT = 5°C
5 = 2.53 × 4.04 g/MM/0.01 × 1
5 = 10.22 × 1/0.01 MM
0.05MM = 10.22
MM= 10.22/0.05
MM= 204.4 g/mol
Learn more: brainly.com/question/2292439
Answer:
60.12 miles
Explanation:
Using the calculation formula shown below:
![t_{1/2} =\frac{t}{[tex]log_{2}](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%20%3D%5Cfrac%7Bt%7D%7B%5Btex%5Dlog_%7B2%7D)
\frac{N_{o} }{N_{t} } }[/tex]
where:
is the half life, 
is the original amount of F-18, and 
is the remaining amount of F-18 at time t.
Generally, F-18 has an half life of 1.83 hours.
Therefore:
![t = 1.83*[tex]log_{2}](https://tex.z-dn.net/?f=t%20%3D%201.83%2A%5Btex%5Dlog_%7B2%7D)
\frac{100}{68} = 1.02 hours[/tex]
Therefore using a speed of 59 miles/hour, the closeness of the hospital is:
distance = speed*time = 59*1.02 = 60.12 miles
Answer:
15.5 km
Explanation:
1.55 x 10^4 m means 1.55 x 10000 = 15,500 m
1 km = 1000 meters
To convert to km we divide by 1000
So 15,500/1000
= 15.5 km
The molar mass of CO2 is 44 grams per mole.
165 grams / 44 grams per mole of CO2 = 3.75 moles CO2
Using Avogadro’s law where 1 mole of substance equals
6.023 x 10^23 molecules
3.75 moles CO2 (6.023 x 10^23 molecules /mole) = 2.26 x 10^24 molecules CO2
