Answer : Group 14 elements are likely to have substances that have both metal and non-metallic properties.
Explanation :
Metalloid : It is a type of element whose properties lies in between the metals and non-metals.
There are commonly six metalloids : Boron(group 13), Silicon & Germanium(group 14), Arsenic & Antimony(group 15), Tellurium(group 16).
Properties of Metalloids :
- Metalloids look like metals but behave largely like non-metals.
- Metalloids are solid, brittle and lustrous.
- Metalloids has ability to conduct electricity.
Therefore, Group 14 elements are likely to have substances that have both metal and non-metallic properties.
Explanation:
The mole is simply a very large number,
6.022
×
10
23
, that has a special property. If I have
6.022
×
10
23
hydrogen atoms, I have a mass of 1 gram of hydrogen atoms . If I have
6.022
×
10
23
H
2
molecules, I have a mass of 2 gram of hydrogen molecules. If I have
6.022
×
10
23
C
atoms, I have (approximately!) 12 grams.
The mole is thus the link between the micro world of atoms and molecules, and the macro world of grams and litres, the which we can easily measure by mass or volume. The masses for a mole of each element are given on the periodic table as the atomic weight. So, if have 12 g of
C
, I know, fairly precisely, how many atoms of carbon I have. Given this quantity, I know how many molecules of
O
2
are required to react
Answer:
Redox but not combustion
Explanation:
2K(s) + 2H₂O(l) → 2KOH(aq) + H₂(g)
This is a redox reaction, because the oxidation number of K increases from 0 to +1, while that of H decreases from +1 to 0.
It is not a combustion reaction, because combustion is the reaction
with O₂.
The equation for the combustion of potassium would be
4K(s) + O₂(g) ⟶ 2K₂O(s)
Percent by mass of platinum in white gold = 100% - 45% = 55%
We let x be the mass of the white which is 45% gold and 55% platinum.
Mass of gold in white gold = m x 0.45
where m is the total mass.
From the given above, we formulate the equation that would allow us to determine the mass of white gold.
154 = x (0.45)
x = 342.22 g
Then, we determine the amount of platinum.
mass of platinum = (342.22 g)(0.55)
mass of platinum = 188.22 grams
Thus, 188.22 grams of platinum is needed.
