The correct answer is both newlands and mendeleev arranged elements according to their atomic masses, but only mendeleev used chemical properties as well.
The explanation:
1- Newlands arranged all the elements known at the time into a table in order of relative atomic mass. ... He then put the similar elements into vertical columns, known as groups.
2- Mendeleev also arranged the elements known at the time in order of relative atomic mass, but he did some other things that made his table much more successful.
He realised that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.
Answer is
3) how much mass per unit of volume is in a substance
You didn't give options but seedless vascular plants are plants that contain vascular tissue, but do not produce flowers or seeds so for example ferns and horsetails
The answer is C) <span>The sample was broken down by the electric current and formed a new substance that could burn. Therefore, the original liquid is a compound. </span>
<u>Answer:</u> The amount of element X remain after 40 years is 18.75 grams
<u>Explanation:</u>
We are given:
Total time period = 40 years
One half life = 10 years
Calculating the number of half lives,
To calculate the amount of element X after 4 half lives, we use the equation:
where,
a = amount of X after n-half lives
= initial amount of X = 300 g
n = number of half lives = 4
Putting values in above equation, we get:
Hence, the amount of element X remain after 40 years is 18.75 grams