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Her discovery of radium and polonium.
She was the first woman to win a nobel prize and a second one as well!
Marie Curie was the first women to be appointed as the director of the physics lab at Sorbonne.
She was also the first woman to become a professor at the University of Paris.
She helped make radiology units which were again portable and those assisted the field surgeons during the war.
Hope this helps :))
Answer:
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Answer: -
15.55 M
35.325 molal
Explanation: -
Let the volume of the solution be 1000 mL.
Density of nitric acid = 1.42 g/ mL
Total Mass of nitric acid Solution = Volume of nitric acid x Density of nitric acid
= 1000 mL x 1.42 g/ mL
= 1420 g.
Percentage of HNO₃ = 69%
Amount of HNO₃ = 
= 979.8 g
Molar mass of HNO₃ = 1 x 1 + 14 x 1 + 16 x 3 = 63 g /mol
Number of moles of HNO₃ = 
= 15.55 mol
Molarity is defined as number of moles per 1000 mL
We had taken 1000 mL as volume and found it to contain 15.55 moles.
Molarity of HNO₃ = 15.55 M
Mass of water = Total mass of nitric acid solution - mass of nitric acid
= 1420 - 979.8
= 440.2 g
So we see that 440.2 g of water contains 15.55 moles of HNO₃
Molality is defined as number of moles of HNO₃ present per 1000 g of water.
Molality of HNO₃ = 
= 35.325 molal
ANSWERS:
Group 2 metal carbonates, nitrates and hydroxides decompose to heat to give the corresponding metal oxide and release CO2, NO2 and O2, and H2O respectively. The thermal stability increases down the group as theionic character of the compounds increases down the group.