<h3><u>Answer;</u></h3>
A dense substance that is hard and incompressible
<h3><u>Explanation</u>;</h3>
- <em><u>Crystals are solids that are made up of particles such as molecules, atoms or ions, </u></em>which are arrange in a highly ordered microscopic structure, forming a crystal lattice which extends in all directions.
- Examples of crystals include<em><u> quartz,</u></em> that is made up of silicon (iV) oxide molecules that are arranged in a lattice,<u><em>table salt</em></u> is another example that is made up of sodium and chloride ions that are arranged in a lattice
- Crystals are very ordered, they may be made up of atoms of the same elements or atoms of different elements such as in the case of table salt.
Answer:
When excess of carbon dioxide is passed in lime water, calcium carbonate is converted to calcium bicarbonate which is soluble, hence the milkiness due to calcium carbonate disappears.
Explanation:
Ca(OH)2+CO2 → CaCO3 (Milkiness) ↓+H2O
CaCO3+H2O+CO2 → Ca(HCO3)2 (soluble)
I think it’s C atomic radius and numbers of unshielded protons
Answer:
Example
0.5 mol of sodium hydroxide is dissolved in 2 dm3 of water. Calculate the concentration of the sodium hydroxide solution formed.
Concentration =
Concentration = 0.25 mol/dm3
Volume units
Volumes used in concentration calculations must be in dm3, not in cm3. It is useful to know that 1 dm3 = 1000 cm3. This means:
divide by 1000 to convert from cm3 to dm3
multiply by 1000 to convert from dm3 to cm3
For example, 250 cm3 is 0.25 dm3 (250 ÷ 1000). It is often easiest to convert from cm3 to dm3 before continuing with a concentration calculation.
Question
100 cm3 of dilute hydrochloric acid contains 0.02 mol of dissolved hydrogen chloride. Calculate the concentration of the acid in mol/dm3.
Reveal answer
Converting between units
The relative formula mass of the solute is used to convert between mol/dm3 and g/dm3:
to convert from mol/dm3 to g/dm3, multiply by the relative formula mass
to convert from g/dm3 to mol/dm3, divide by the relative formula mass
Remember: the molar mass is the Ar or Mr in grams per mol.
Example
Calculate the concentration of 0.1 mol/dm3 sodium hydroxide solution in g/dm3. (Mr of NaOH = 40)
Concentration = 0.1 × 40
= 4 g/dm3
I looked up what is the molecular formula for Phosphine and got this: PH3
Hope this helps! Let my know if this was correct.