Explanation:
It is known that atoms that have same number of valence electrons will show similar chemical properties.
So, when we move from left to right across a period there occurs increase in number of valence electrons of each element. But when we move down a group then number of valence electrons remain the same.
Hence, elements of same group will show similar chemical properties.
Therefore, we can conclude that elements marked as 2 and 3 will have similar chemical properties.
A physical exothermic process
8%
Explanation:
In a DNA molecule the no. of Adenine bases equal to that of Thymine bases
The no. of Cytosine bases equal to that of Guamine bases.
If we take no. of Thymine bases as x and no. of Cytosine bases as y,
Adenine + Thymine + Cytosine + Guamine = 100
x + x + y+y = 100
2( x+y) = 100
x+y = 50
y=42
therefore x= 50-42 = 8%
Answer:
1.The electonic configuration of elements and their position in the periodic table are related to each other, From the electronic configuration of the elements, we can determine the period and the group to which the element belongs
Let's consider, sodium with atomic number 11 and k, l, and M shells have 2,8,and 1 electrons. since, there are 3 principal energy levels so we concluded sodium belongs to third period M Shell(valance shell) has only 1 electrons. so sodium belongs to group 1.
2. Entire D-block elements are known as Transition Elements.
3. Group 17 is the halogen group.
4. Main group of elements are...... 1,2, and 13 through 18.
5. Group 18 are the noble gas elements .
12. a). Smaller
b). Increases
c). More reactive
d). Softer
7. a). k › Ca › Ge › Br › Kr
b). Ra › Ba › Sr › Ca › Mg › Be
9. a). Ca(calcium) ion is smaller.
b). Cl(chlorine) atom is smaller.
c). Mg(magnesium) atom is smaller.
10. a). F(fluorine)
b). Sr(strontium)
c). Pb(lead)
d). At(Astatine)
Answer:
only thing close I can see would be aluminun
Explanation:
atomic number of 13 and 8 2nd electrons in its shell.
