Explanation:
To solve this problem, we simply use the periodic table of elements which groups elements based on their atomic numbers.
The atomic number of an element is the number of protons it contains. The protons are the positively charged particles within an atom.
- The vertical arrangement of elements on the periodic table is the group.
- The horizontal arrangement of elements is the period.
Now;
Noble gases belongs to group 18
Alkali earth metals belongs to group 2
Halogens belongs to group 17
Alkali metals belongs to group 1
Transition metals belongs to group 3-12
Answer:
2.122×10^25atoms
Explanation:
number of moles=mass/molar mass
7.05moles= mass of pyridine/79
reacting mass of pyridine=556.95
C5H5N= (12×5)+(5)+(14)=79
C5=60
to find the mass of carbon in 556.95g of pyridine we take the stoichometric ratio
60[C5] -----> 79[C5H5N]
x[C5] --------> 556.95g[C5H5N]
cross multiply
x=(60×556.95)/79
x=423g of carbon
moles=mass/molar mass
moles of carbon=423/12
moles=35.25moles of carbon
moles=number of particles/Avogadro's constant
35.25=number of particles/6.02×10^23
number of particles=2.122×10^25atoms of carbon
Answer:
a. 1,2,and 3.
Explanation:
When something turns liquid, e.g. metal, you need to heat it. When something turns gas, e.g. water, you need to heat it. And when something goes directly from solid to gas, e.g. dry ice, carbon dioxide, you need to add heat to it. hope this helps! Please mark brainiest.
<u>Answer:</u> No crystals of potassium sulfate will be seen at 0°C for the given amount.
<u>Explanation:</u>
We are given:
Mass of potassium nitrate = 47.6 g
Mass of potassium sulfate = 8.4 g
Mass of water = 130. g
Solubility of potassium sulfate in water at 0°C = 7.4 g/100 g
This means that 7.4 grams of potassium sulfate is soluble in 100 grams of water
Applying unitary method:
In 100 grams of water, the amount of potassium sulfate dissolved is 7.4 grams
So, in 130 grams of water, the amount of potassium sulfate dissolved will be
As, the soluble amount is greater than the given amount of potassium sulfate
This means that, all of potassium sulfate will be dissolved.
Hence, no crystals of potassium sulfate will be seen at 0°C for the given amount.