Answer:
See explanation
Explanation:
The slope of a graph in which mass was plotted against volume is the density of the object. Density of objects have been measured and recorded in standard handbooks for the purpose of reference. If the density of an unknown substance is measured, it can now be compared with the density of known substances recorded in standard handbooks such as the handbook of physics and chemistry. By so doing, the unknown substance can be identified.
According to standard handbooks, the density of copper is 8.96 g/ml while that of nickel is 8.908 g/ml. If the average slope obtained is around 8.96 g/ml, then the metal is copper and not nickel.
An alternative to this method is to measure the refractive index of the piece of metal and compare the average values observed with the contents of standard handbooks in order to identify the unknown metal.
Answer:
it will be the koala and the water buffalo
Explanation:
The answer is A there i 1 atom
Answer:
1.195 g of Arsenic.
Explanation:
Equation of the reaction:
Ga(l) + As(s) → GaAs(s).
Calculating the limiting reagent by:
Number of moles of:
Gallium:
Molar mass of Gallium = 69.7 g/mol.
Mass = 4 g
Number of moles = mass/molar mass
= 4/69.7
= 0.0574 mol.
Arsenic:
Molar mass of Arsenic = 75 g/mol.
Mass = 5.5 g
Number of moles = mass/molar mass
= 5.5/75
= 0.0733 mol
Therefore, using stoichiometry since 1 mole of Gallium reacted with 1 mole of Arsenic. The limiting reagent is Gallium.
Excess reagent is Arsenic.
Number of moles excess = 0.0733 - 0.0574
= 0.0159 moles
Mass of the excess Arsenic left =
Molar Mass * number of moles
= 0.0159 * 75
= 1.195 g of Arsenic.
Manganese since 25 protons is 25 atomic number