1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Lelu [443]
3 years ago
7

I've a question from chemistry...

Chemistry
1 answer:
serious [3.7K]3 years ago
3 0
<h3>Answer:</h3>

22.06 Hours

<h3>Explanation:</h3>
  • Half life is the time it takes for a radioactive material or isotope to decay by half of its initial amount.

We are given;

Radioactive isotope Iodine-133

Initial counts per minute = 3150 counts

Counts after decay = 3055 per minute

Time taken = 1 hour

But, we know that to calculate the remaining amount of the radioactive isotope, then,

Remaining amount = Initial amount × 0.5^n , where n is the number of half-lives.

Therefore;

3055 counts = 3150 × 0.5^n

0.5^n = 0.9698

To get n

n = log 1 ÷ log 0.9698

 = 0.044

But, n is given by dividing time and the number of half lifes

Therefore, half life = time ÷ Number of half lives

                              = 1 hour ÷ 0.044

                              = 22.60 hours

Therefore, the half life of iodine-133 is 22.60 hours

You might be interested in
The IUPAC rules permit the use of common names for a number of familiar phenols and aryl ethers. These common names are listed h
fgiga [73]

Explanation:

a. Vanillin(4-hydroxy-3-methoxybenzaldehyde):

In its structure hydroxl group will be present on para position of the benzaldehyde ring and methoxy group on meta position.

b. Thymol (2-isopropyl-5-methylphenol):

In its structure isopropyl group will be present on ortho position of the phenol ring and methyl group on meta position.

c. Carvacrol (5-isopropyl-2-methylphenol):

In its structure isopropyl group will be present opposite to methyl group which is present ortho position in a phenol ring.

d. Eugenol (4-allyl-2-methoxyphenol):.

In its structure allyl group will be present on para position of the phenol ring and methoxy group on ortho position.

e. Gallic acid (3,4,5-trihydroxybenzoic acid):

In its structure hydroxyl group will be present on both meta positions and on para position of the benzoic acid ring.

f. Salicyl alcohol (o-hydroxybenzyl alcohol):

In its structure, -CH_2OH group is linkedto benzene ring and in respect to that hydroxyl group is present at ortho position of the ring.

6 0
3 years ago
What is the electron configuration for vanadium (V)? The Periodic Table A. 1s22s22p63s23p64s24d3 B. 1s22s22p63s23p63d5 C. 1s22s2
kramer

The electronic configuration for vanadium (V) in the periodic table is as follows: 1s2 2s2 2p6 3s2 3p6 4s2 3d3 (option D).

<h3>What is electronic configuration?</h3>

Electronic configuration is the the arrangement of electrons in an atom, molecule, or other physical structure like a crystal.

Vanadium is the 23rd element on the periodic table and has chemical symbol V with atomic number 23. It is a transition metal, used in the production of special steels.

This suggests that the electronic configuration of Vanadium will be written as follows: 1s2 2s2 2p6 3s2 3p6 4s2 3d3

Therefore, the electronic configuration for vanadium (V) in the periodic table is as follows: 1s2 2s2 2p6 3s2 3p6 4s2 3d3.

Learn more about electronic configuration at: brainly.com/question/14283892

#SPJ1

5 0
2 years ago
What is the independent variable in the graph?
n200080 [17]
It is c because I did it already
5 0
3 years ago
Which of the following is equal to 5.3 mm3? 5.3 x 10-6 m3 5.3 x 10-9 m3 5.3 x 10-6 cm3 5.3 x 103 cm3
Shalnov [3]
The answer to this item is determined by using the proper conversion factors and the dimensional analysis. For the given units, meter and centimeters, the conversion from millimeters are as shown below,
 
   1 m = 1000 mm
    1 cm = 10 mm

Conversion of 5.3 mm³ to m³.
 
       = (5.3 mm³)(1 m/1000 mm)³ = 5.3 x 10⁻⁹ m³

Conversion of 5.3 mm³ to cm³.

      = (5.3 mm³)(1 cm/10 mm)³ = 5.3 x 10⁻³ cm³

The answer to this item is therefore letter B. 5.3 x 10⁻⁹ m³. 
3 0
3 years ago
(image attached)
densk [106]

Answer:

Option (A).

Explanation:

A). Structural formula

    Structural formula of a chemical compound represents a graphic structure of a molecule.

B). Chemical formula

    Chemical formula shows the chemical proportions of the atoms which constitute a molecule of the compound.

C). Space filling model

    Space filling model is a 3-D molecular model in which atoms are represented by the spheres whose radii are proportional to the radii of the atoms and distances between the atoms are proportional to the distances between the atomic nuclei.

D). A ball and stick model

    This model shows the 3-D positions of the atoms and the bonds between them.

    In this model atoms are represented by the spheres and bonds connected by the sticks.

Therefore, model shown is STRUCTURAL FORMULA.

Option (A) is the answer.

4 0
3 years ago
Read 2 more answers
Other questions:
  • What is true of diffusion?
    14·1 answer
  • What is the heat of vaporization of nitrous oxide in kJ/mol?
    15·1 answer
  • which of these elements is least likely to react with other elements? explain. a) calcium b) argon c) sodium d) nitrogen e) oxyg
    9·1 answer
  • What is the atom formula for <br> (NaPO3)6 ?
    14·2 answers
  • Write the expression for K in terms of the solubility, s, for each salt, when dissolved in water. nickel(II) cyanide silver hydr
    12·1 answer
  • A student reports the following measurements for a set of pennies: 102.0mL, 91.0 g. What is the density of the pennies.
    6·1 answer
  • If the aluminum block is initially at 25 ∘C∘C, what is the final temperature of the block after the evaporation of the alcohol?
    14·1 answer
  • A local factory has been dumping chemicals into a nearby river that resulted in the death of many aquatic dwelling organisms. Th
    12·1 answer
  • I will give brainlyst for this so pls help
    15·2 answers
  • What is mole in chemistry?
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!