Answer: Between 1 and 2.
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
............(1)
where,
a = amount of reactant left after n-half lives = 40
= Initial amount of the reactant = 100
n = number of half lives
Putting in the values we get:

taking log on both sides


Thus half-lives that have elapsed is between 1 and 2
Answer:
Last week, it was announced that four new elements would be added to the periodic table, a collaboration from researchers in Russia, Japan and the U.S. Elements 113, 115, 117, and 118, which will complete the seventh row, are superheavy elements, that have an atomic number greater than 104.
Explanation:
In a branched chain of amino acids
Carbon 14 because it has an approximate half life of 5000 years.
The other gas which the article mentioned is Helium gas.
<h3>What is Compression?</h3>
This refers to the squeezing or shortening of a substance which is most often done by increasing the temperature.
The information scientists hope to gain by compressing this gas into a solid is by studying the molecular structures and using it in the production of other substances which is why Nitrogen and Helium are the gases being studied in this scenario.
Read more about Compression here brainly.com/question/17266589