<span>He used the patterns he found in properties of known elements to predict the properties of unknown elements.</span>
Answer: Think of each polar bond in a molecule as a little arrow pointing from positive to negative. So, the geometry of the molecule determines the direction that the bond dipole vectors point. The polarity of the molecule results from adding up all these individual bond dipoles.
Answer:
yeh they are all correct .
Answer:
A potentiometric pH meter is used to measure the pH of a solution.
Explanation:
A pH meter is an common instrument that is used to measure the hydrogen-ion concentration in aqueous solutions , the meter indicates its acidity or alkalinity and is expressed as pH.
The pH meter measures the difference in electrical potential between a pH electrode and a reference electrode, hence the pH meter is often called a potentiometric pH meter. The difference in electrical potential is related to the pH of the solution.
Potentiometric pH meters consists of a simple electronic amplifier and a pair of electrodes, alternatively it may consist of a combination electrode, and some form of display calibrated in pH units. It usually has a glass electrode and a reference electrode, or a combination electrode. The electrodes, or probes, are inserted into the solution to be tested and pH values are read off.
Answer: 85 minutes
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Half life for second order kinetics is given by:
= half life = 15 min
k = rate constant =?
= initial concentration = 100 (say)
Integrated rate law for second order kinetics is given by:
a= concentration left after time t =
Thus after 85 minutes after the start of the reaction, it will be 85% complete.