Remembering that
d = m ÷ v
d = ?
m = 104 g
v = 21 cm³
Therefore:
d = 104 ÷ 21
<span>d = 4,95 g÷cm³</span>
Answer:
The 197Au isotope has 79 protons, 79 electrons and 118 neutrons
Explanation:
Step 1: The isotope = 197Au
Step 2: Calculate neutrons, electrons and protons
197 = Number of protons + number of neutrons
Isotopes always have the same proton number ( is the same as the atomic number). For Gold (Au) is this 79.
The number of electrons is equal to the number of protons in a neutral atom. Since we have 79 protons, there are also 79 electrons.
All isotopes of Au have a different number of neutrons.
The number of neutrons = 197 -79 = 118 neutrons
The 197Au isotope has 79 protons, 79 electrons and 118 neutrons
Answer:
2.038 seconds.
Explanation:
So, in the question above we are given the following parameters in order to solve this question. We are given a rate constant of 0.500 s^-, initial concentration= 0.860 M and final concentration= 0.310 M,the time,t =??.
Assuming that the equation for the first order of reaction is given below,that is;
A ---------------------------------> products.
Recall the formula below;
B= B° e^-kt.
Therefore, e^-kt = B/B°.
-kt = ln B/B°.
kt= ln B°/B.
Where B° and B are the amount of the initial concentration and the amount of the concentration remaining, k is the rate constant and t = time taken for the concentration to decrease.
So, we have; time taken,t = ln( 0.860/.310)/0.500.
==> ln 2.77/0.500.
==> time taken,t =2.038 seconds.
Answer:
The new volume of the balloon will be 6046.28 L
Explanation:
Initial pressure (P1) = 99 kpa
initial volume (V1) = 3000 L
Initial temperature = 39 C = 39 + 273 = 312 K
Final pressure (P2) = 45.5 kpa
Final temperature = 16 C = 16 +273 = 289K
Final volume = ????
To calculate the final volume using the general gas equation
P1 V1 / T1 = P2 V2 / T2
make V2 the subject of the formular
V2 = 99000 ×3000× 289 / 45500×312
V2 = 85833000 /14196
V2 = 6046.28 litres