Having resources? i guess...
maybe it is critical thinking?
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:
Answer:
- <em>Hydration number:</em> 4
Explanation:
<u>1) Mass of water in the hydrated compound</u>
Mass of water = Mass of the hydrated sample - mass of the dehydrated compound
Mass of water = 30.7 g - 22.9 g = 7.8 g
<u>2) Number of moles of water</u>
- Number of moles = mass in grams / molar mass
- molar mass of H₂O = 2×1.008 g/mol + 15.999 g*mol = 18.015 g/mol
- Number of moles of H₂O = 7.9 g / 18.015 g/mol = 0.439 mol
<u>3) Number of moles of Strontium nitrate dehydrated, Sr (NO₃)₂</u>
- The mass of strontium nitrate dehydrated is the constant mass obtained after heating = 22.9 g
- Molar mass of Sr (NO₃)₂ : 211.63 g/mol (you can obtain it from a internet or calculate using the atomic masses of each element from a periodic table).
- Number of moles of Sr (NO₃)₂ = 22.9 g / 211.63 g/mol = 0.108 mol
<u>4) Ratio</u>
- 0.439 mol H₂O / 0.108 mol Sr(NO₃)₂ ≈ 4 mol H₂O : 1 mol Sr (NO₃)₂
Which means that the hydration number is 4.
Protons: charge +1, have a mass of 1 and are found in the nucleus
Neutrons: charge 0, have a mass of 1 and are found in the nucleus
Electrons: charge -1, have a mass of 1/840 and are found on the outside of the nucleus
hope that helps
Answer:
weigh it and divide the weight by the molecular weight. :) good luck!!
Explanation:
