Answer:
2 8 8 2 is a correct answer
Well in this
case, silver
nitrate is reduced:
Ag<span>+ </span><span>+ </span>e<span>− </span>→ Ag(s) ↓
Meanwhile, the aluminum
is oxidized forming a positive ion:
Al(s<span>) → </span>Al<span>3+ </span><span>+ 3</span>e−
To get the
overall reaction, we add the half
equations so that the electrons are eliminated:
Al(s<span>) + 3</span>Ag<span>+ </span><span>→ </span>Al<span>3+ </span><span>+ 3</span>Ag(s)
And similarly:
Al(s<span>) + 3</span>AgNO3(aq<span>) → </span>Al(NO3)3(aq<span>) + 3</span>Ag(s<span>)</span>
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: Answer:
"The arrangement of atoms or ions in a crystal " is described by the terms body-centered cubic and face-centered cubic.
Explanation:
Face centred cubic system explains the crystal structure where an atom is present at each cubic corner of the crystal and the centre of each cube face. Meaningfully, a closed packed plane where at each "face of the cube" atoms touch the alongside face diagonals.
Whereas in body centric cube system has the lattice point present at the 8 corners of cell and an additional one at the center of the cell. Thus, both explains how the atom or ions are placed or arranged in a crystal.
Explanation: Hope this helps :)
To calculate the <span>δ h, we must balance first the reaction:
NO + 0.5O2 -----> NO2
Then we write all the reactions,
2O3 -----> 3O2 </span><span>δ h = -426 kj eq. (1)
O2 -----> 2O </span><span>δ h = 490 kj eq. (2)
NO + O3 -----> NO2 + O2 </span><span>δ h = -200 kj eq. (3)
We divide eq. (1) by 2, we get
</span>O3 -----> 1.5O2 δ h = -213 kj eq. (4)
Then, we subtract eq. (3) by eq. (4)
NO + O3 -----> NO2 + O2 δ h = -200 kj
- (O3 -----> 1.5 O2 δ h = -213 kj)
NO -----> NO2 - 0.5O2 δ h = 13 kj eq. (5)
eq. (2) divided by -2. (Note: Dividing or multiplying by negative number reverses the reaction)
O -----> 0.5O2 <span>δ h = -245 kj eq. (6)
</span>
Add eq. (6) to eq. (5), we get
NO -----> NO2 - 0.5O2 δ h = 13 kj
+ O -----> 0.5O2 δ h = -245 kj
NO + O ----> NO2 δ h = -232 kj
<em>ANSWER:</em> <em>NO + O ----> NO2 δ h = -232 kj</em>
