Answer;
A) Stage 1: Chlorophyll captures light energy. Stage 2: Light energy is converted to chemical energy.
Explanation;
-Photosynthesis is the process by which green plants use energy from the sun, water and carbon dioxide to make organic compounds such as simple sugars together with release of oxygen.
-The process occurs in tow stages; light-dependent stage and light independent stage. During light dependent stage, chlorophyll absorbs sunlight and uses it to split water molecules into hydrogen ions and oxygen atoms. In the light independent stage carbon (iv) dioxide is fixed and the result is organic compound; the light energy is converted to chemical energy.
Answer : (C) Hafnium is the most likely identity of the given substance.
Solution : Given,
Mass of given substance (m) = 46.9 g
Volume of given substance (V) = 3.5 
First, find the Density of given substance.
Formula used :
Now,put all the values in this formula, we get
= 13.4 g/
So, we conclude that the density of given substance (13.4 g/) is approximately equal to the density of Mercury and Hafnium (13.53 and 13.31 g/ respectively).
According to the question the substance is solid at room temperature but Mercury is liquid at room temperature. So, Mercury is not identical to the given substance.
Another element i.e, Hafnium is the element whose density is approximately equal to the given substance and also solid at room temperature. And we know that the melting point of solid is high.
So, Hafnium is the most likely element which is the identity of the given substance.
Answer:
a) H2SO4 + 2KOH -> 2H2O + K2SO4
b) 9.809 ml
Explanation:
Number of Moles = Mass/ Molar Mass
Therefore: Mass = Number of moles * Molar Mass
--------------------------------------------
Molar mass of H2SO4:
H2= 2.02
S= 32.07
O4= 64
--------------------------------------------
H2SO4 has the molar mass of 98.09
--------------------------------------------
the Moles of H2SO4 is given to be 0.100M
Therefore:
Mass= 98.09*0.1
= 9.809g
---------------------------------------------------
Assuming that 1 g= 1 ml, the volume of sulfuric acid is 9.809 ml.
1. A. All the elements in the column have similar chemical properties.
2. Substances on the periodic table cannot be broken down into other substances and are therefore elements.
