Answer:
57 mins
Explanation:
From the question given above, the following data were obtained:
Half life (t₁/₂) = 19 mins
Original amount (N₀) = 100 g
Amount remaining (N) = 12.5 g
Time (t) =?
Next, we shall determine the number of half-lives (n) that wound have elapse for 12.5 g of the sample to remain. This can be obtained as follow:
Original amount (N₀) = 100 g
Amount remaining (N) = 12.5 g
Number of half-lives (n) =?
N = 1/2ⁿ × N₀
12.5 = 1/2ⁿ × 100
Cross multiply
12.5 × 2ⁿ = 100
Divide both side by 12.5
2ⁿ = 100 /12.5
2ⁿ = 8
Express 8 index with 2 as the base
2ⁿ = 2³
n = 3
Finally, we shall determine the time taken for 100 g of the isotope to decay to 12.5 g. This can be obtained as follow:
Half life (t₁/₂) = 19 mins
Number of half-lives (n) = 3
Time (t) =?
t = n × t₁/₂
t = 3 × 19
t = 57 mins
Thus, it will take 57 mins 100 g of the isotope to decay to 12.5 g.
Sodium has 11 protons, therefore number of neutrons must be 23 – 11 = 12 neutrons.
Sodium has 12 neutrons.
<h3>What are neutrons?</h3>
The neutron is a subatomic particle with the symbol n that is slightly heavier than a proton and has a neutral charge (i.e., neither a positive nor a negative charge). Atoms' nuclei are made up of protons and neutrons. Protons and neutrons are both referred to as nucleons because of how similarly they function inside the nucleus and because they both have masses that are about equal to one atomic mass unit. Nuclear physics describes their characteristics and interactions.
The arrangement of electrons around an atom's hefty nucleus largely determines its chemical characteristics. The amount of protons, or atomic number, determines the charge of the nucleus, which determines the electron configuration.
To learn more about neutrons from the given link:
brainly.com/question/5013687
#SPJ4
C. It increases and the pH stays constant.
The best and most correct answer among the choices provided by the question is the second choice , b. sodium hydroxide .
Hope my answer would be a great help for you. If you have more questions feel free to ask here at Brainly.
The fragrant organic compounds found in many flowers that contain a carbonyl group bonded to a carbon atom and a hydrogen atom are called aldehydes.