Answer:
2
Explanation:
The 1 & 2 are both signifigant becuase they are presented in scientific notation.
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
Answer:
<h3>The answer is 0.75 g/mL</h3>
Explanation:
The density of a substance can be found by using the formula
From the question
mass = 90 g
volume = 120 mL
We have
We have the final answer as
<h3>0.75 g/mL</h3>
Hope this helps you
Answer:burning of fossil fuels and the decrease of oxygen and the increase of carbon dioxide
Explanation:
<span>Copper(II) nitrate. Hope i cleared your doubt</span>
