Correct answer: B
Cooling curve is the plot of temperature versus time as the sample is allowed to cool. In a cooling curve, we start at a temperature greater than the boiling point. At this temperature, the sample is in gaseous state. At the boiling point, there is no change in temperature as the gaseous and liquid states are in equilibrium. As the temperature reduces further, the liquid starts to condense and at the melting point of the sample the liquid undergoes phase transition to solid state. At the melting temperature, a second plateau is observed as the temperature remains unchanged. At temperatures below the melting point, the sample exists as a solid.
So from the curve, the second plateau is observed at around -111
. This point represents the phase transition from liquid to solid state.
+2 D. because this atom is magnesium and mag. has a charge of +2
<span>A machine is a device that does work. Most machines consist of a number of elements, such as gears and ball bearings, that work together in a complex way. Nonetheless, no matter how complex they are, all machines are based in some way on six types of simple machines. These six types of machines are the lever, the wheel and axle, the pulley, the inclined plane, the wedge, and t</span>
To determine the strength of potassium permanganate with a standard solution of oxalic acid.
A redox reaction is a reaction that involves both reduction and oxidation, it involves a reducing agent which looses electrons and undergoes oxidation and an oxidizing agent that gains electrons (reduction). I believe the following are true about redox reactions; Electrons move from one substance to another, One atom gains electrons and one looses electrons.