Is a measure of how heavy atoms are. It's the ratio of the average mass per atom of an element from a given sample to 1/12 the mass of a carbon-12 atom."
Answer:
m = 700 g
Explanation:
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
Symbol:
The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
Given data:
Density of octane = 0.700 g/cm³
Volume = 1 L
Mass = ?
Formula:
D=m/v
D= density
m=mass
V=volume
First of all we will convert the volume in cm³ because density is given in g/cm³ unit.
1 L = 1000 cm³
Now we will put the values in formula:
d= m/v
m = v × d
m = 1000 cm³ × 0.700 g/cm³
m = 700 g
Answer : The correct option is, (B)
Explanation :
Balance equation : Balanced equation are those equation in which the number of atoms of each element and the total charge must be same on products side and reactants side.
In the given options, only option (B) equation has correct formula and also a balanced equation.

while the other options has incorrect formulas and also an unbalanced equations.
The correct equation for option A is, 
The correct equation for option C is, 
The correct equation for option D is, 
Hence, the correct answer is, (B) 
<u>Answer:</u>
<em>Atomic number 75 is dedicated to an element named rhenium and has been given Re as its chemical name.</em>
<u>Explanation:</u>
With a really low concentration it is one of the rarest metals that is found in Earth's crust.
Like all other elements rhenium also has certain isotopes among with 185 and 187 are the most stable ones. Hence these two are the ones that are naturally available abundance is 34% and 63% respectively.