Answer: Boron is the element which has properties of both metals and nonmetals.
Explanation:
Metals are defined as the elements which loose electrons to attain stable electronic configuration. They attain positive charge and form cation. Example: Zinc (Zn), Aluminium (Al) , copper (Cu)
Non-metals are defined as the elements which gain electrons to attain stable electronic configuration. They attain negative charge and form anion. Example: Chlorine (Cl) , Sulphur (S)
Metalloids are defined as the elements which show properties of both metals and non-metals. There are 7 metalloids in the periodic table. They are Boron (B) , Silicon (Si) , Germanium (Ge) , Arsenic (As) , Antimony (Sb), Tellurium (Te) and Polonium (Po).
Thus boron is the element which has properties of both metals and nonmetals.
<span>To calculate the atomic mass of a single atom of an element, add up the mass of protons and neutrons. Example: Find the atomic mass of an isotope of carbon that has 7 neutrons. You can see from the periodic table that carbon has an atomic number of 6, which is its number of protons.</span>
Answer:
0.0300 moles of H₂
Explanation:
The original equation is PV = nRT. We need to change this to show moles (n).
n = 
It's important to convert your values to match the constant (r) in terms of units.
30.0 kPa = 0.296 atm
2500 mL = 2.50 L
27 °C = 300 K
Now, plug those values in to solve:
n = 
- for the sake of keeping the problem clean, I didn't include the units but you should just to make sure everything cancels out :)
Finally, you are left with n = 0.0300 moles of H₂
The average atomic mass of iron : 55.85 amu
<h3>Further explanation
</h3>
The elements in nature have several types of isotopes
Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
An atomic mass unit = amu is a r<em>elative atomic mass of 1/12 the mass of an atom of carbon-12.
</em>
The 'amu' unit has now been replaced with a unit of 'u' only
Atomic mass is the average atomic mass of all its isotopes
atomic mass X = mass isotope 1 . % + mass isotope 2.%
...
The average atomic mass of iron
