Answer:
An ice pack uses friction and the chemicals inside make it mix to make it cold
Explanation:
<span>Get a periodic table of elements. ...Find your element on the periodic table. ...Locate the element's atomic number. ...Determine the number of electrons. ...Look for the atomic mass of the element. ...<span>Subtract the atomic number from the atomic mass.</span></span>
Answer:
Mole fraction of 
= 0.58
Mole fraction of 
= 0.42
Explanation:
Let the mass of and = x g
Molar mass of = 33.035 g/mol
The formula for the calculation of moles is shown below:
Thus,
Molar mass of = 46.07 g/mol
Thus,
So, according to definition of mole fraction:
Mole fraction of = 1 - 0.58 = 0.42
Noble gases' outer shells are already filled with 8 electrons (other than He, which has 2, but is still filled and stable). Atoms bond with other elements to fill their outer shell, but they don't need to do that and are already stable.
Answer:4
Explanation:
If we carefully observe the electronegativity of the elements in question
P-2.19
N-3.04
C-2.55
Si-1.9
H-2.2
SiH4 is definitely more polar than CH4 hence greater dipole forces of a higher boiling point. NH3 is more polar than PH3 hence NH3 has greater dipole forces and a higher boiling point. Electronegative differences influences the polarity of a bond. The greater the electro negativity difference between bonding atoms, the greater the dipole forces and the greater the boiling point.
