Answer:
16 cm
Explanation:
Because when you look at the ruler, it shows the length as 16 cm
Answer:
a. Approximately 
.
b. Approximately 
.
Explanation:
The unit of concentration "
" is equivalent to "
", which means "moles per liter."
However, the volume of both solutions were given in mililiters 
. Convert these volumes to liters:
.
.
In a solution of volume 
where the concentration of a solute is 
, there would be 
(moles of) formula units of this solute.
Calculate the number of moles of 
formula units in each of the two solutions:
Solution in a.:
.
Solution in b.:
.
What volume of that 
(same as 
) solution would contain that many
For the solution in a.:
.
Convert the unit of that volume to milliliters:
.
Similarly, for the solution in b.:
.
Convert the unit of that volume to milliliters:
.
The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as system's mass cannot change, so quantity cannot be added nor removed. Hence, the quantity of mass is conserved over time.
The law implies that mass can neither be created nor destroyed, although it may be rearranged in space, or the entities associated with it may be changed in form. For example, in chemical reactions, the mass of the chemical components before the reaction is equal to the mass of the components after the reaction. Thus, during any chemical reaction and low-energy thermodynamic processes in an isolated system, the total mass of the reactants, or starting materials, must be equal to the mass of the products.
According to the Law of Conservation, all atoms of the reactant(s) must equal the atoms of the product(s).
As a result, we need to balance chemical equations. We do this by adding in coefficients to the reactants and/or products. The compound(s) itself/themselves DOES NOT CHANGE.
Answer:
Knowing this, researchers from the University of Southern Denmark decided to investigate the size of these hypothetical hidden particles. According to the team, dark matter could weigh more than 10 billion billion (10^9) times more than a proton.
Explanation:
If this is true, a single dark matter particle could weigh about 1 microgram, which is about one-third the mass of a human cell (a typical human cell weighs about 3.5 micrograms), and right under the threshold for a particle to become a black hole.
Molar mass Na = 23g/mol
46g = 456/2 = 2mol
1mol = 6.022*10^23 atoms
2mol = 2*6.022*10623
= 1.204*10^24 atoms
