The concentration of the drug stock solution is 1.5*10^-9 M i.e. 1.5 * 10^-9 moles of the drug per Liter of the solution
Therefore, the number of moles present in 1 ml i.e. 1*10^-3 L of the solution would be = 1 *10^-3 L * 1.5 * 10^-9 moles/1 L = 1.5 * 10^-12 moles
1 mole of the drug will contain 6.023*10^23 drug molecules
Therefore, 1.5*10^-12 moles of the drug will correspond to :
1.5 * 10^-12 moles * 6.023*10^23 molecules/1 mole = 9.035 * 10^11 molecules
The number of cancer cells = 2.0 * 10^5
Hence the ratio = drug molecules/cancer cells
= 9.035 *10^11/2.0 *10^5
= 4.5 * 10^6
Answer:
Krypton does not react with anything, but it reacts with fluorine gas
Explanation:
A physical change<span> in a substance doesn't </span>change<span> what the substance is. In a </span>chemical change<span> where there is a </span>chemical reaction<span>, a new substance is formed and energy is either given off or absorbed.</span>
Answer: C. High surface tension
Explanation:
Water has high specific heat as it require high heat to raise the temperature of 1 g of water through 
.
Surface tension is the net downward force acting on the surface of liquids due to the cohesive nature of liquids.
Water molecules are bonded by strong hydrogen bonding between the hydrogen atom and the electronegative oxygen atom making it polar. Thus water molecules present on the surface are strongly attracted by the molecules present below the surface and thus act as a stretched membrane.
The surface acquires a minimum surface are and thus acquire a spherical shape.
