Your Question: There are two kinds of elements that didn't appear on the periodic table until after 1892. What kinds are they and why do you think it took so long to discover them?
The Answer: Moseley’s analysis enabled chemists to refine the table further and reveal more gaps, which suggested that there were more new elements waiting to be discovered, with atomic numbers 43, 61, 72 and 75. Scientists subsequently found these elements—now known as technetium, promethium, hafnium and rhenium, respectively.
Explanation: Physicist Henry Moseley discovered the atomic number of each element using x-rays, which led to more accurate organization of the periodic table. We will cover his life and discovery of the relationship between atomic number and x-ray frequency, known as Moseley's Law.
Remember to read study guides, lessons and notes to rely yourself on; key to success is working hard. Good Luck!
Answer:
Helium
In the sun, hydrogen is converted to __<u>Helium</u>__ through nuclear fusion.
The amount of water that must be added to 6.0 M silver nitrate to make 500mL of 1.2 M solution is : 2000 mL
<u>Given data :</u>
Concentration of siilver nitrate ( M₁ ) = 6.0 M
volume of solution ( V₁ ) = 500 mL
Conc of solution ( M₂ )= 1.2 M
<h3>Determine the amount of water that must be added</h3>
we will apply the equation below
M₁V₁ = M₂V₂ ---- ( 1 )
where : V₂ = V₁ + water added ---- ( 2 )
V₂ ( Final volume ) = ( M₁V₁ ) / M₂
= ( 6 * 500 ) / 1.2
= 2500 mL
Back to eqaution ( 2 )
2500 mL = 500 mL + added water
therefore ; added water = 2500 - 500
= 2000 mL
Hence we can conclude that The amount of water that must be added to 6.0 M silver nitrate to make 500mL of 1.2 M solution is : 2000 mL.
Learn more about Volume : brainly.com/question/12410983
#SPJ1
Answer:
Jimmy wrote two expressions that are not equivalent
Explanation:
24+6=30 while 6(4+2) equals 36 because if you distribute the 6 to 4 (which equals 24) then the 6 to 2 (which equals 12) and add 24 and 12 together, you get 36. So, 24+6 =/= 6(4+2). Hopefully this is correct!
