Answer:
1.25 gram of cesium-137 will remain.
Explanation:
Given data:
Half life of cesium-137 = 30 year
Mass of cesium-137 = 5.0 g
Mass remain after 60 years = ?
Solution:
Number of half lives passed = Time elapsed / half life
Number of half lives passed = 60 year / 30 year
Number of half lives passed = 2
At time zero = 5.0 g
At first half life = 5.0 g/2 = 2.5 g
At 2nd half life = 2.5 g/ 2 = 1.25 g
Thus. 1.25 gram of cesium-137 will remain.
1st one is E
2nd one is also E
Answer is: H₂O → H⁺ + OH⁻.
Water dissociates (autoionization) to form hydrogen ions (H⁺) and hydroxide (OH⁻) ions. The protons (H⁺) hydrate as hydroxonium ions( H₃O⁺).
The Kw (the ionic product for water) at 25°C is 1·10⁻¹⁴ mol²/dm⁶ or 1·10⁻¹⁴ M². Concentration of hydrogen ions and hydroxide ions in pure water are the same.
Answer:
Horse latitude, trade winds
Explanation:
- The area of the low pressure or the calm consists of the variable light winds that blow near the equator are known to the marines as the doldrums and they form a circuital pattern near the earth atmosphere.
- Forms at a center of the near the higher pressure systems called as the horse latitudes where the trade winds at the surface are weak and variable and this zone is found generally in latitudes of the 30° North and South of the equator and move in an east to west direction.
