Answer:
4.47 x 10²² atoms
Explanation:
Given parameters:
Mass of Bismuth = 15.5g
Unknown:
Number of atoms = ?
Solution:
To find the number atoms, first solve for the number of moles in this element first.
Number of moles = 
Number of moles = 
= 0.074mole
So:
1 mole of a substance contains 6.02 x 10²³ atoms
0.074 mole of Bismuth will contain 0.074 x 6.02 x 10²³ atoms
= 4.47 x 10²² atoms
Answer:
Rubidium
Explanation:
Rubidium has atomic number 37 and belong to group one alkali metals and has one valence electron at the outermost shell whiz is 5s1
Answer: C) 0.020 m
Explanation:
Molality of a solution is defined as the number of moles of solute dissolved per kg of the solvent.
where,
n = moles of solute
= weight of solvent in g
Mole fraction of 
is = 
i.e. moles of is present in 1 mole of solution.
Moles of solute 
=
moles of solvent (water) = 1 - = 0.99
weight of solvent =
Molality =
Thus approximate molality of in this solution is 0.020 m
Answer:
It was significant because thanks to Miller's experiment, it was possible to test many years later and with modern techniques, the progress of the evolution of life on Earth.
Explanation:
In Miller's experiment, he subjected a mixture of methane, ammonia, hydrogen, carbon dioxide, nitrogen and water to strong electric shocks and high temperatures. He noted that organic molecules such as glucose, amino acids such as glycine, alanine, glutamic acid and aspartic acid were formed. Subsequently, in 2008 other scientists analyzed these compounds using more sensitive devices. Their analyzes found the formation of 20 amino acids (proteins) and 6 components found in the nucleus of the cells, thus checking the progress of the evolution of life on Earth.
1023 molecules or atoms depending on substance
