Answer:
Bubbling/Foaming
Heat is produced
Explanation:
A chemical reaction has occurred if
1. There is a change in colour
2. Formation of a precipitate
3. Formation of a gas
4. Change in temperature
5. Change of smell
In the reaction of hydrogen peroxide and potassium iodide, the solution quickly rises which shows the formation of gas. This means it is a chemical reaction.
The beaker/test tube/whatever you used should also become warm because it is an exothermic reaction. This means its a chemical reaction
Explanation:
Quite a number of properties varies across a period. Some remains constant whereas others decreases.
As one moves from left to right;
- The energy level remains the same.
- The ionization energy increases progressively as a result of increasing nuclear charge.
- Electron affinity increases from left to right.
- Electronegativity increases.
- Electropositivity decreases.
learn more:
Periodic table brainly.com/question/2014634
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(missing in Q) : Calculate the concentration of CO & H2 & H2O when the system returns the equilibrium???
when the reaction equation is:
C(s) + H2O(g) ↔ H2(g) + CO(g)
∴ Kc = [H2] [CO] / [H2O]
and we have Kc = 0.0393 (given missing in the question)
when the O2 is added so, the reaction will be:
2H2(g) + O2(g) → 2H2O(g)
that means that 0.15 mol H2 gives 0.15 mol of H2O
∴ by using ICE table:
[H2O] [H2] [CO]
initial 0.57 + 0.15 0 0.15
change -X +X +X
Equ (0.72-X) X (0.15+X)
by substitution:
0.0393 = X (0.15+X) / (0.72-X) by solving for X
∴ X = 0.098
∴[H2] = X = 0.098 M
∴[CO] = 0.15 + X
= 0.15 + 0.098 = 0.248 M
∴[H2O] = 0.72 - X
= 0.72 - 0.098
= 0.622 M
This element is found in group 3A, period 3
<h3>Further explanation
</h3>
The maximum number of electrons that can be filled in the nth electron shell is 2n²(n=shell)
-
K shell (n = 1) maximum 2 x 1² = 2 electrons
- L shell (n = 2) maximum 2 x 2² = 8 electrons
- M shell (n = 3) maximum 2 x 3² = 18 electrons
- N shell (n = 4) maximum 2 x 4² = 32 electrons
Electron configuration of element X : 2.8.3 , so :
K shell = 2 ⇒1s²
L shell = 8⇒2s²2p⁶
M shell = 3⇒ 3s²3p¹
Block p: group 13-18 (has a 2p-6p configuration), also called a representative element because it includes metals, non-metals and metalloids
The outer shell 3s²3p¹ : located in group 3A and period 3
group⇒valence electron ⇒3
period⇒the greatest value of the quantum number n⇒3
That question shoulda be true
