Answer: BF3
Explanation: boron needs 4 electron to obtain octet and Fluorine has just one. For the valence shell to be completely filled it will have to form BF4- with 4 fluorine atom surrounding it.
A quantitative observation is not necessarily more useful than a non-quantitative one. However, quantitative observations do allow one to find trends.
(a), the sun rising is a non-quantitative observation.
(b), knowledge of the numerical relationship between the weight on the Moon and on Earth, is a quantitative observation.
(c), watching ice float on water does not involve a measurement; therefore, it must be a qualitative observation.
(d) the fact that we know that the water pump won’t work for depths more than 34 feet makes it quantitative. Again, seeing numbers is a giveaway that it’s a quantitative <span>observation. Quantitative is where you deal with numbers.</span>
Use the ideal gas formula-----> PV= nRT
P= 2.50 atm
V= 250 mL= 0.250 L
n= 0.100 moles
R= 0.0821 atmxL/molesxK
T= ?
T= PV/nR
T= (2.50 atm x 0.250 L) / (0.100 moles x 0.0821)= 76.1 K
Magma in quiet eruptions has a low content in silica , while in explosive eruptions, it has a high Content in silica. A volcano that erupts quietly has magma that is low in silica. Low-silica magma has low viscosity and flows easily. A volcano that erupts explosively has magma that is high in silica. High-silica magma has high viscosity, making it thick and sticky, thus it flows slowly.
