Answer:
emulsion
Explanation:
An emulsion is a mixture of two or more liquids that are normally immiscible. Emulsions are part of a more general class of two-phase systems of matter called colloids.
False. elements in the same period have the same number of shells while elements in the same group have the same number of valence electrons.
I got 134.91 but if you round it you’ll get 135
Complete Question:
To aid in the prevention of tooth decay, it is recommended that drinking water contain 0.800 ppm fluoride. How many grams of F− must be added to a cylindrical water reservoir having a diameter of 2.02 × 102 m and a depth of 87.32 m?
Answer:
2.23x10⁶ g
Explanation:
The concentration of the fluoride (F⁻) must be 0.800 ppm, which is 0.800 parts per million, so the water must have 0.800 g of F⁻/ 1000000 g of the solution. The density of the water at room temperature is 997 kg/m³ = 997x10³ g/m³. So, the concentration of the fluoride will be:
0.800 g of F⁻/ 1000000 g of the solution * 997x10³ g/m³
0.7976 g/m³
The volume of the reservoir is the volume of the cylinder: area of the base * depth. The base is a circumference, which has an area:
A = πR², where R is the radius = 1.01x10² m (half of the diameter)
A = π*(1.01x10²)²
A = 32047 m²
The volume is then:
V = 32047 * 87.32
V = 2.7983x10⁶ m³
The mass of the F⁻ is the concentration multiplied by the volume:
m = 0.7976 * 2.7983x10⁶
m = 2.23x10⁶ g
Answer: True
Explanation:
The matter exists as solid, liquid or gas. These are called the states of matter. The change of matter from one state to another can be achieved by heating or cooling.
The solid state can be converted into liquid state by providing heat to solid. The heat will make the particles move farther, resulting into liquid state.
Similarly when liquid state is provided heat, it changes to gaseous state. The heat will make the particles move much more faster.
Thus the statement that when heat flows to an object, it can change states is True.
