Answer:
Measuring a pencil in meters would be very difficult, as a single meter is much longer than one pencil. Also, measuring a hallway in millimeters would be very difficult considering how small millimeters are in comparison to a hallway. However, if you switch these two then they would work very well.
Answer:
3.4321229*10^23 molecules.
Explanation:
1 mole of CBr4 contains 6.0221409*10^23 molecules (Avogadro's Number).
The molar mass of this compound is 12.011 + 4(79.904)
= 331.627 g.
So the answer is (189/ 331.627) * 6.0221409*10^23
= 3.4321229*10^23 molecules.
Answer:
potential energy (im positive that its right)
<span>Answer:
pH = 2.7, therefore amount of H+ needed is 10^-2.7 M
u haf 80 ml of hcl and 90 ml of naoh left, therefore 20 ml of hcl used, and 10ml of naoh used.
mols of H+ = 0.02 x 7 x 10^-2 = 1.4 x 10^-3
mols of OH- = 0.01 x 5 x 10^-2 = 5 x 10^-4
H+ and OH- neutralise each other, so remaining mols of H+ = 9 x 10^-4
u need 10^-2.7 mols of H+, so 10^-2.7 - 9 x 10^-4 = 0.001095 mol
vol of HCL needed = 0.001095 / 7 x 10^-2 = 0.0156 L = 15.6 mL</span>
Generally (but far from universally), the elements within a group have similar characteristics. Antimony, nitrogen, and arsenic are all part of the same group as phosphorous (the pnictogens, or group 5A). Oxygen is not in this group, but rather in an adjacent group (the chalcogens, or group 6A). Thus, the answer here should be oxygen.
That said, there can be very significant differences in characteristics among the elements within a group, and that is certainly the case here. For example, free nitrogen exists predominantly as a molecular gas (N₂) and makes up about 78% of the atmosphere we breathe. Elemental arsenic (As), while in the same group as nitrogen, is naturally found in the solid state and is poisonous to humans (arsenic is sometimes included among the toxic heavy metals, although it’s technically a metalloid).