Answer:
Thorium 227 (also known as Radioactinium)
Answer:
Wilhelm Conrad Roentgen (1845-1923)
Antoine Henri Becquerel (1852-1908)
Pierre (1859-1906) and Marie (1867-1934) Curie
Explanation:
Wilhelm Conrad Roentgen (1845-1923)
Contribution: Discovery of x-rays in 1901.
Antoine Henri Becquerel (1852-1908)
Contribution: He discovered that radioactivity is the separation of x-rays and document and the difference between two.
Pierre (1859-1906) and Marie (1867-1934) Curie
Contribution: She discovered Polonium and Radium in1911
The same speed of light, the fastest possible
darkness is just the absence of light therefore once light leaves darkness returns. making darkness have the same speed of light
Maybe this will help you in a way,<span> some physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others.
- hope this helps you well .</span>
<u>Answer:</u>
Mass of C in 3.40 g of HCN =1.51 gram.
<u>Explanation:</u>
Mass of sample of HCN = 7.99 g
Mass of H in 7.99 g of HCN = 0.296 g
Mass of N in 7.99 g of HCN = 4.14 g
Mass of C in 7.99 g of HCN = (7.99-0.296-4.14) = 3.554 g
Now mass of HCN = 3.40 g
Mass of C in 3.40 g of HCN = 
So mass of C in 3.40 g of HCN =1.51 gram.
