Answer:
38
Explanation:
Symbol: Sr
Atomic mass: 87.62 u
Electrons per shell: 2,8,18,8,2
Atomic number: 38
Electron configuration: [Kr] 5s2
Van der Waals radius: 255 pm
Valence electrons: two
Answer:
Molarity = 0.24 M
Explanation:
Given data:
Number of moles of Mg(NO₃)₂ = 0.181 mol
Volume of solution = 0.750 L
Molarity of solution = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
by putting values,
Molarity = 0.181 mol / 0.750 L
Molarity = 0.24 M
The rows in the top third - This group consists of elements like Sodium, Magnesium, Potassium and Calcium on the right and Chlorine, Carbon, Nitrogen and Oxygen on the left.
Sodium and Chlorine are components of salt, a very important compound of our blood, essential for transferring electrical signals from the brain to the rest of the body and vice versa. Calcium is the building block of our bones, while Magnesium and potassium ensure proper functioning of our organs.
so this is right answer
For reasons that are unclear, no eukaryotic enzymes can break the triple bond of N2. The reduction of N2 to NH3 (nitrogen fixation) is limited to prokaryotes and is catalysed by nitrogenase. Since most of the nitrogen entering the biosphere (around 100 million metric tonnes of N2 per annum) does so through nitrogenase activity (lightning contributes about 10%), those plants that associate with nitrogen-fixing bacteria have a significant selective advantage under conditions of limiting nitrogen.
You should make a density trap, you get different liquids with different density's ( corn starch , water , alcohol , syrup) and pour them into a big vase and the different density's will sit on top of each other . the best thing to do is to use food coloring so that each level is a different color.
