Hepta is seven and tetra is four, so option c is your answer
The Bohr atomic model, relying on quantum mechanics, built upon the Rutherford model to explain the orbits of electrons.
Answer:150g of gold
Explanation: There is a lot more gold and gold is significantly significantly more dense than lithium
Answer:

Explanation:
Given that,
The dimension of a square chunk of plastic is 5 cm × 5 cm × 5 cm
Mass, m = 200 g
We need to find its density
Density = mass/volume
It will form a cube. It volume = side³
So,

Hence density is 
The empirical formula is K₂O.
The empirical formula is the <em>simplest whole-number ratio</em> of atoms in a compound.
The <em>ratio of atom</em>s is the same as the <em>ratio of moles</em>.
So, our job is to calculate the <em>molar ratio</em> of K to O.
Step 1. Calculate the <em>moles of each element
</em>
Moles of K = 32.1 g K × (1 mol K/(39.10 g K =) = 0.8210 mol K
Moles of O = 6.57 g O × (1 mol O/16.00 g O) = 0.4106 mol 0
Step 2. Calculate the <em>molar ratio of each elemen</em>t
Divide each number by the smallest number of moles and round off to an integer
K:O = 0.8210:0.4106 = 1.999:1 ≈ 2:1
Step 3: Write the <em>empirical formula
</em>
EF = K₂O