Answer:
The answer to your question is the letter C. 2.906 x 10²³ atoms
Explanation:
Data
mass of Lead = 100 g
The Number of atoms = ?
Process
1.- Look for the atomic number of Lead in the periodic table
Atomic number = 207.2 g
2.- Use proportions and the Avogadro's number to calculate the number of atoms.
207.2 g ------------------ 6.023 x 10²³ atoms
100 g ----------------- x
x = (100 x 6.023 x 10²³) / 207.2
x = 6.025 x 10²⁵ / 207.2
x = 2.906 x 10²³ atoms
Mario places 10 mL of water in a test tube and heats the liquid over a Bunsen burner for 2 minutes. After removing the test tube from the Bunsen burner, there are 6 mL of water left in the test tube. This experiment is a good example of a <span>physical change involving phase changes. </span>
Answer:
A reaction rate is a measure of how fast a reactant disappears or a product forms during a reaction.
Explanation:
It is usually defined as the change in concentration per unit time:
Δ(concentration)/Δt
The units are (moles per litre) per second.
In symbols, the units are mol/(L·s) or mol·L^-1 s^-1.
<span> C.The results of the Michelson-Morley experiment did not fit the theory of the luminiferous ether, so the theory had to be rejected. </span>
Answer:
Phosphorous has the smallest atomic size.
Explanation:
As we know these elements belong to same period means there valence shell is the same. So moving from left to right along the period the shell number remains constant but the number of protons and electrons increases. So, due to increase in number of protons the nuclear charge increases hence attracts the valence electrons more effectively resulting in the decrease of atomic size.
Elements and their atomic radius are as follow,
<span><span>Magnesium 0.160 nm
</span><span>
Aluminium 0.130 nm
</span><span>
Silicon 0.118 nm
</span><span>
Phosphorus <span>0.110 nm</span></span></span>
