1. Which sample contains a total of 9.0 * 10 ^ 23 atoms ? A) 0.50 mole of HCI B) 0.75 mole of H 2 O C) 1.5 moles of Cu D) 1.5 moles of H 2

The sample that contains 9.0 x atoms would be 1.5 moles of Cu.

1 mole of a substance contains 6.0 x   atoms of the same substance. Thus:

Hence, the only sample that contains  9.0 x   atoms is 1.5 mole of Cu.

More on number of atoms of substances can be found here: link?

c. 1.5 moles of Cu will contain a total of 9.0 * 10 ^ 23 atoms.

Explanation:

To convert moles into atoms,  the molar amount and number of atom is multiplied by Avagadro's number.

Avagadro's number is 6.022×  

So applying the formula in the given sample:

A) 0.5×6.022×

   3.01× atoms.

B) 0.75 mole of H20

O.75×6.022×

= 4.5166×  atoms.

C) 1.5 moles of Cu

  1.5×6.022×

  =  9.033×

D). 1.5 moles of H2

1.5 × 2 × 6.022 ×

= 18.066 × atoms   because H2 is 2 moles of hydrogen.

Atom is the smallest entity of matter having property of the element to which it is a part.

adding or remove a gaseous reactant or product changes the concentrations. if the concentration of reactant or product is increased, the system will shift away from the side in which concentration was increased (i.e. if the concentration of reactants is increased, the system will shift toward the products. if more products are added, the system will shift to form more reactants). conversely, if the concentration of reactant or product is decreased, the system will shift toward the side in which concentration was decreased (i.e. if reactants are removed, the system will shift to form more reactants. if the concentration of products is decreased, the equilibrium will shift toward the products).

explanation:

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.