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
miss Akunina [59]
2 years ago
5

How many half-lives will pass by the time 1.56% of I-131 is present? B. Approximately how many days does that equal? *

Chemistry
1 answer:
serg [7]2 years ago
6 0

Answer: Hmmmmm that's crazy....

There are a couple of equations one could use for this type of problem, but I find the following to be the easiest to use and to understand.

Fraction remaining (FR) = 0.5n

n = number of half lives that have elapsed

In this problem, we need to find n and are given the FR, which is 1.56% or 0.0156 (as a fraction).

0.0156 = 0.5n

log 0.0156 = n log 0.5

-1.81 = -0.301 n

n = 6.0 half lives have elapsed

Explanation:

Just wanted to help. Hopefully it's correct wouldn't want to waster your time ;)

You might be interested in
Give me number of significant figures in the number 40
dangina [55]

1 significant figure, because there is no decimal after the zero the zero doesn't count.

5 0
3 years ago
State general trend for metal properties as you go left to right across a period
qwelly [4]

Periodic trends are specific patterns that are present in the periodic table that illustrate different aspects of a certain element, including its size and its electronic properties. Major periodic trends include: electronegativity, ionization energy, electron affinity, atomic radius, melting point, and metallic character. Periodic trends, arising from the arrangement of the periodic table, provide chemists with an invaluable tool to quickly predict an element's properties. These trends exist because of the similar atomic structure of the elements within their respective group families or periods, and because of the periodic nature of the elements.

Electronegativity Trends

Electronegativity can be understood as a chemical property describing an atom's ability to attract and bind with electrons. Because electronegativity is a qualitative property, there is no standardized method for calculating electronegativity. However, the most common scale for quantifying electronegativity is the Pauling scale (Table A2), named after the chemist Linus Pauling. The numbers assigned by the Pauling scale are dimensionless due to the qualitative nature of electronegativity. Electronegativity values for each element can be found on certain periodic tables. An example is provided below.


From left to right across a period of elements, electronegativity increases. If the valence shell of an atom is less than half full, it requires less energy to lose an electron than to gain one. Conversely, if the valence shell is more than half full, it is easier to pull an electron into the valence shell than to donate one.

From top to bottom down a group, electronegativity decreases. This is because atomic number increases down a group, and thus there is an increased distance between the valence electrons and nucleus, or a greater atomic radius.

Important exceptions of the above rules include the noble gases, lanthanides, and actinides. The noble gases possess a complete valence shell and do not usually attract electrons. The lanthanides and actinides possess more complicated chemistry that does not generally follow any trends. Therefore, noble gases, lanthanides, and actinides do not have electronegativity values.

As for the transition metals, although they have electronegativity values, there is little variance among them across the period and up and down a group. This is because their metallic properties affect their ability to attract electrons as easily as the other elements.

According to these two general trends, the most electronegative element is fluorine, with 3.98 Pauling units.



6 0
3 years ago
Pls help me I beg you
just olya [345]

Answer:

Es la c

Explanation:

Espero que te ayude

6 0
3 years ago
Read 2 more answers
What happens when nitrogen and hydrogen comes in contact at high temperature and pressure in presence of iron powder and molybde
Sidana [21]

Answer:

<h2>Ammonia Gas</h2>

Explanation:

It result in formation of ammonia gas.

N2 + 3H2 ---<u>iron</u><u>/</u><u>molybdenum</u><u>/</u><u>high</u><u> </u>temp/pres--- > 2 NH3

It forms ammonia gas.

Please mark branliest if you are satisfied with the answer. Thanking in anticipation.

6 0
3 years ago
Answer this: 15/x = 23/3<br> and this: 30/x = 90/3
prohojiy [21]

Answer:

the 1st one is impossible second is x = 1

Explanation:

7 0
2 years ago
Read 2 more answers
Other questions:
  • What are the products of burning fuel
    12·1 answer
  • BRAINLIEST ANSWER.... How many bonding and nonbonding electrons are on the nitrogen atom in NO2?
    5·1 answer
  • Who taught us how planets move?
    13·1 answer
  • Based on these data, what is the value of the formation constant, Kf, of [Cu(NH3)4]2+? [Cu 2+ ]=6.47x10 -15 kf=
    12·1 answer
  • If the volume of a substance is measured with a graduated cylinder, the unit of measure for volume will be:
    10·1 answer
  • Which of these would not be a reason why earth can support life but other planets in our solar system do not have life? A) Earth
    13·2 answers
  • 7th grade science lol help​
    14·1 answer
  • What is the we
    14·1 answer
  • Pls helllllpppppp!!!!!<br> how was the interior of the atom was experimentally dicovered?
    10·1 answer
  • The organelle that serves as a microtubule organizing center during cell division is the
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!