Answer:
the empirical formula of the metal fluoride.
Explanation:
Mass of copper heated = 8.249 g
Mass of copper fluoride formed = 13.18 g
Mass of fluorine gas in copper fluoride = x

Moles of copper :

Moles of fluorine:

For the empirical formula divide the smallest mole of an element with all the moles of elements present in the compound.

The empirical formula of the copper fluoride = 
the empirical formula of the metal fluoride.
Answer:
Antigens (more info below)
Explanation:
Antigens determine the blood type and may be either proteins or sugar molecule complexes (polysaccharides). Genes in the blood group antigen group provide instructions for the production of antigen proteins. Blood group antigen proteins serve a variety of functions within the red blood cell membrane.
hope I helped!
The answer to this question is A. Humidity.. because humitity causes steam
The concentrations : 0.15 M
pH=11.21
<h3>Further explanation</h3>
The ionization of ammonia in water :
NH₃+H₂O⇒NH₄OH
NH₃+H₂O⇒NH₄⁺ + OH⁻
The concentrations of all species present in the solution = 0.15 M
Kb=1.8 x 10⁻⁵
M=0.15
![\tt [OH^-]=\sqrt{Kb.M}\\\\(OH^-]=\sqrt{1.8\times 10^{-5}\times 0.15}\\\\(OH^-]=\sqrt{2.7\times 10^{-6}}=1.64\times 10^{-3}](https://tex.z-dn.net/?f=%5Ctt%20%5BOH%5E-%5D%3D%5Csqrt%7BKb.M%7D%5C%5C%5C%5C%28OH%5E-%5D%3D%5Csqrt%7B1.8%5Ctimes%2010%5E%7B-5%7D%5Ctimes%200.15%7D%5C%5C%5C%5C%28OH%5E-%5D%3D%5Csqrt%7B2.7%5Ctimes%2010%5E%7B-6%7D%7D%3D1.64%5Ctimes%2010%5E%7B-3%7D)
![\tt pOH=-log[OH^-]\\\\pOH=3-log~1.64=2.79\\\\pH=14-2.79=11.21](https://tex.z-dn.net/?f=%5Ctt%20pOH%3D-log%5BOH%5E-%5D%5C%5C%5C%5CpOH%3D3-log~1.64%3D2.79%5C%5C%5C%5CpH%3D14-2.79%3D11.21)