Answer:
Br
|
Br-P-Br
|
Br
Explanation:
To calculate the valance electrons, look at the periodic table to find the valance electrons for each atom and add them together. P is in column 5A, so it has 5, Br is in column 7A, so it has 7 (multiply by 4 since there are 4 Br atoms to give 28) and there is a 1- charge, so add one more electron. 5+28+1=34, so there are 34 electrons to place. P would be the central atom, so place it in the middle. Place each Br around the P (as shown above) with a a single line connecting it. Each line represents 2 electrons, so 8 total have been place, leaving 26 remaining. Place 6 electrons around each Br (2 on each of the unbonded sides), which leaves 2 electrons remaining. The remaining pair of unbound electrons will be attached to the P between any two Br atoms. Phosphorus doesn't have to follow the octet rule, so it actually ends up with 10 valance electrons.
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.
Jupiter Saturn Mars Earth Sun
I'm pretty sure it's D. Compounds
Salt water is an example of a solution, and a solution is a type of mixture, so by multiple choice logic none can be the right answer! Seriously though - mixture are combinations of two compounds that are physically combined but do not undergo a chemical reaction with one another to produce a new compound. For instance, when you dissolve salt in water, you don't produce any new products, and you can boil away the water to leave only the salt (a physical method of separation). You cannot separate a compound by physical means because by definition this would be a chemical reaction as you're breaking bonds.
To find moles from grams divide the number of moles by the molar mass...
32.7g/18.01 which is 1.82 using significant figure rules
