Answer:
17. The iron metal is oxidized to form the iron oxide known as rust.
19.A saturated solution will not dissolve any more solute and any extra solute added will simply stay as it is, without dissolving. An unsaturated solution has less solute than its solubility and hence can still add more solute, till it reaches the saturation level.
26 An Overflowing Population. The swelling American population played a large part in the decision Americans made to head, The Government Opens Up New Land. The American government itself encouraged its citizens to move west
32. The periodic table was first assembled in 1869 by a Russian chemist named Dmitri Mendeleev. He came up with a way of organizing the elements that were known at the time, arranged them in order of atomic weight, and then grouped them into rows and columns based on their chemical and physical properties. Here is a unique "Mayan" format Periodic Table. Elements in the same group are those that are in a single vertical line from top to bottom. They have the most in common between the two directions. They share the same number of electrons in their valence subshells.
Explanation:
Explanation:
In a covalent bond the electrons are simultaneously attracted by the two atomic nuclei.
Balanced chemical reaction: 2KCl + Pb(NO₃)₂ → PbCl₂ + 2KNO₃.
According to principle of mass conservation, number of atoms must be equal on both side of balanced chemical reaction.
KCl is potassium chloride.
Pb(NO₃)₂ is lead(II) nitrate.
KNO₃ is potassium nitrate.
PbCl₂ is lead(II) chloride.
Answer:
Start and end times; distance run.
Step-by-step explanation:
Average speed = distance/time.
Kaila should record the distance run, the time she started, and the time she ended her run.
The difference between the start and end times gives the time for the run.
If she inserts her numbers into the formula, she will get her average running speed.
M₁ = mass of water = 75 g
T₁ = initial temperature of water = 23.1 °C
c₁ = specific heat of water = 4.186 J/g°C
m₂ = mass of limestone = 62.6 g
T₂ = initial temperature of limestone = ?
c₂ = specific heat of limestone = 0.921 J/g°C
T = equilibrium temperature = 51.9 °C
using conservation of heat
Heat lost by limestone = heat gained by water
m₂c₂(T₂ - T) = m₁c₁(T - T₁)
inserting the values
(62.6) (0.921) (T₂ - 51.9) = (75) (4.186) (51.9 - 23.1)
T₂ = 208.73 °C
in three significant figures
T₂ = 209 °C
