See the correct answer is b.)PbS
Atomic mass silicon = 28.085 u
1 mol Si ---------------- 28.085 g
? ------------------------ 245 g
245 x 1 / 28.085 =><span> 8.72 mol</span>
<span>answer A</span>
Answer:
answer-
The relative atomic mass = 204.4
explanation:
Thallium -203 = 30%
Thallium -205 = 70%
Therefore ,
relative mass of thallium = (30×203 + 70×205)/100
relative mass of thallium = (20440)/100
relative mass of thallium = 204.40 amu
Thus,
relative atomic mass of thalium =204.4 ( to 1 decimal place)
Answer:
9 (1-2x²)
Explanation:
The given expression is:
30 - 9x²*2 - 21 - 4 + 4
The first step is to compute the multiplication. This will give:
30 - 18x² - 21 - 4 + 4
Then, we will add like terms as follows:
(30-21-4+4) - 18x²
= 9 - 18x²
Finally, we can take the 9 as a common factor from both terms, this will give:
9 (1-2x²)
Hope this helps :)
Answer:
Explanation:
There are 3 types of plastids :-
1) Chloroplasts:- The green plastids which contain chlorophyll pigments for photosynthesis.
2) Chromoplasts:-The coloured plastids for pigment synthesis and storage.
3) Leucoplasts:- The colourless plastids for monoterpene synthesis found in non- photosynthetic parts of the plants.
They are of three types:-
a) Amyloplasts- stores starch.
b) Proteinoplasts- stores proteins.
c) Elaioplasts- stores fats and oils.