Answer:
Elements having same valence electrons are placed in <u>same group.</u>
Explanation:
First, let's start with some basic concepts of modern periodic table:
1. Modern Periodic table : It is the arrangement of element in the increasing order of their atomic numbers
The Modern periodic table is divided into Periods and groups .
Periods : These are the horizontal rows. There are seven periods in the periodic table . Period 1 has 2 element. Period two and three has 8 elements , period 4 and 5 have 18 elements and the period 6 and 7 have 32 elements.
Same period have same number of atomic orbital(Shell)
Group : The group is the vertical columns . There are 18 groups in the modern periodic table.Those element which have same group number will also have same number of electron in their outermost shell. The number of electron in the outermost shell determines the valency of the element.
So, elements showing same valency are placed in same group.
All alkali are place in group 1 and have 1 valance electron in the outermost shell
27g x 1cm^2/2.7g = answer in cm^2
Grams cancel out
Answer: 1. moles
2. 90 mg
Explanation:
According to stoichiometry:
1 mole of ozone is removed by 2 moles of sodium iodide.
Thus moles of ozone is removed by = moles of sodium iodide.
Thus moles of sodium iodide are needed to remove moles of
2.
According to stoichiometry:
1 mole of ozone is removed by 2 moles of sodium iodide.
Thus 0.0003 moles of ozone is removed by = moles of sodium iodide.
Mass of sodium iodide= (1g=1000mg)
Thus 90 mg of sodium iodide are needed to remove 13.31 mg of .
Answer: Temperature
Explanation: Temperature is a measure of average kinetic energy of particles in an object. The hotter the substance, higher is the average kinetic energy of its constituent particles. When we heat a substance, the particles that constitute the substance gain some energy and begin to move faster.