From the calculations, the half life of the material is 6.5 days.
<h3>What is radioactivity?</h3>
The term radioactivity has to do with the spontaneous disintegration of a specie.
Uisng the formula;
N=Noe^-kt
N= amount at time t = 0.135 Ci or 4.995 ×10^9 Bq
No = amount initially present = 1.75 x 10^12 Bq
k = rate constant = ?
t = time taken = 55 days
Hence;
4.995 ×10^9 = 1.75 x 10^12e^-55k
4.995 ×10^9/1.75 x 10^12 = e^-55k
2.85 * 10^-3 = e^-55k
ln2.85 * 10^-3 = -55k
k = ln2.85 * 10^-3/-55
k = 0.1066 day-1
Half life = 0.693/ 0.1066 day-1
= 6.5 days
Learn more about radioactivity:brainly.com/question/1770619
#SPJ1
People have learnt to make shelters in a way so that they don't get affected by natural disasters that are common in their area. For example, people make houses of complete brick so they are stronger and can withstand a powerful storm
Answer:
Explanation:
We want the energy required for the transition:
CO 2
(
s
)
+
Δ
→
C
O
2
(
g
)
Explanation:
We assume that the temperature of the gas and the solid are EQUAL.
And thus we simply have to work out the product:
2
×
10^
3
⋅
g
×
196.3
⋅
J
⋅
g
−
1 to get an answer in Joules as required.
What would be the energy change for the reverse transition:
C
O
2
(
g
)
+
→
C
O
2
(
s
)
?
Answer:
The right option is the 4 one. nucleoid
Prokaryotic cells are simple cells that lack a definite nucleus and some membrane-bound organelles. Prokaryotic cells have a nucleoid region, which is an irregularly-shaped central region of the cell that contains the cell’s genetic information (DNA). Other organelles that can be found in prokaryotic cells include plasma membrane, cell wall, cytoplasm, and ribosomes.
Explanation:
Answer:
The given statement - The main criterion for sigma bond formation is that the two bonded atoms have valence orbitals with lobes that point directly at each other along the line between the two nuclei , is <u>True.</u>
Explanation:
The above statement is correct , because the sigma bond is produced by the head on overlapping, the orbitals should all point in the same direction.
<u>SIGMA BONDS -</u> Sigma bonds (bonds) are the strongest type of covalent chemical bond in chemistry. They're made up of atomic orbitals that collide head-on. For diatomic molecules, sigma bonding is best characterized using the language and tools of symmetry groups.
Head-on overlapping of atomic orbitals produces sigma bonds. The concept of sigma bonding is expanded to include bonding interactions where a single lobe of one orbital overlaps with a single lobe of another. Propane, for example, is made up of ten sigma bonds, one for each of the two CC bonds and one for each of the eight CH bonds.
Hence , the answer is true .
