The half-life of Zn-71 is 2.4 minutes. If you had 100.Og at the beginning, how many grams would be left after 4.8 minutes? Show or describe how you solved
this. *

25 g

Explanation:

Given data:

Half life of Zn-71 = 2.4 min

Mass of Zn-71 = 100 g

Mass left after 4.8 min = ?

Solution:

First of all we will calculate the number of half lives passed.

Number of half lives = Time elapsed / half life

Number of half lives = 4.8 min/ 2.4 min

Number of half lives = 2

At time zero total mass 100 g

At first half life = 100 g/2 = 50 g

At second half life = 50 g/2 = 25 g

Thus, mass left after 4.8 minuets is 25 gram.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.