Answer:
Molar mass of Ca = 40 g / mol , given 123 g Ca is 123/40= 3.075 moles,
1 mole = 6.022 * 10^23 atoms, so 3.075 moles Ca= 18.51*10^23 atoms
Explanation:
A starfish has five equal arms, so a starfish would have 5 lines of symmetry. Hope this helps!
Answer:
speed=5cm/minute
Explanation:
Given at 2:00PM the hermit is at 10cm mark
Also given that the hermit reaches 60cm mark at 2:10PM
Therefore the time elapsed is 10 minutes = 
the distance travelled by the hermit is 60-10=50cm=0.5m
We know that


speed =
m/sec=5cm/minute
Answer:
D
Explanation:
From periodic table : proton number 19 corresponds to K (potassium)
which is very reactive with water
<u>Answer:</u> The molality of solution is 0.740 m.
<u>Explanation:</u>
To calculate the mass of solvent (water), we use the equation:

Volume of water = 750 mL
Density of water = 1 g/mL
Putting values in above equation, we get:

To calculate the molality of solution, we use the equation:

Where,
= Given mass of solute
= 100.0 g
= Molar mass of solute
= 180 g/mol
= Mass of solvent (water) = 750 g
Putting values in above equation, we get:

Hence, the molality of solution is 0.740 m.