Answer: A. the transfer of heat by currents
Explanation: There are three modes of heat transfer:
1) Conduction: This type of heat transfer happens when there is direct contact between the two object. Example: heating a pan on stove.
2) Convection: This type of heat transfer happens when there is a movement of fluid (liquid or gas) due to the movement of hot layers to the top and cold layers to the bottom which leads to convection currents. Example: Heating of swimming pool.
3) Radiation: This type of heat transfer happens when there is direct transfer of energy through space. Example: Heating of earth's surface.
B. The transmission of heat across matter is conduction.
C. The electromagnetic radiation from the surface of an object which is due to the object's temperature is radiation.
D. The transmission of heat across empty space is radiation.
Answer:
B or C
Explanation:
Alchemy rely a lot on the spiritual connections to the four elements and they are fire, water, earth and air while chemistry is a lot more logical, factual and scientific based. Also, chemistry is considered as science, while alchemy is not.
Alchemy was based more on experimentation and had little basis in science. Chemistry utilizes both experimentation and scientific practices. Modern chemistry basically relies on scientific theories and experimental results, but the alchemy was a blend of myths, religion, magic, astrology, philosophy, and spirituality.
B) land cools off much faster than water (creating a air region of high density above land and lower density above sea)
Atoms must have equal numbers of protons and electrons. So to answer your question, yes protons and electrons are the same number.
When Ag₂S dissolves, it dissociates as follows;
Ag₂S ---> 2Ag⁺ + S²⁻
First we need to calculate molar solubility which gives the number of moles dissolved in 1 L of solution.
If molar solubility of Ag₂S is y, then molar solubility of Ag²⁺ and S²⁻ is 2y and y respectively.
ksp gives the solubility constant
ksp = [Ag⁺]²[S²⁻]
ksp = [2y]²[y]
4y³ = 8.00 x 10⁻⁵¹
y³ = 2 x 10⁻⁵¹
y = 1.26 x 10⁻¹⁷ mol/L
molar mass = 247.8 g/mol
solubility of Ag₂S = 1.26 x 10⁻¹⁷ mol/L x 247.8 g/mol = 3.12 x 10⁻¹⁵ g/L
Solubility of Ag₂S = 3.12 x 10⁻¹⁵ g/L
