Answer:
A) 20
B) 40
C) Ca
D) 10
E) 9
F) F
Explanation:
The MASS NUMBER is the number of protons + the number of neutrons.
The ATOMIC NUMBER is the number of protons.
You can take the MASS NUMBER - ATOMIC NUMBER = NUMBER OF NEUTRONS.
Each element is unique and distinguished by the NUMBER OF PROTONS = ATOMIC NUMBER, ie...the number of protons in its nucleus. You can find the element's name and symbol on the Periodic Table.
Using the exponential decay model; we calculate "k"
We know that "A" is half of A0
A = A0 e^(k× 5050)
A/A0 = e^(5050k)
0.5 = e^(5055k)
In (0.5) = 5055k
-0.69315 = 5055k
k = -0.0001371
To calculate how long it will take to decay to 86% of the original mass
0.86 = e^(-0.0001371t)
In (0.86) = -0.0001371t
-0.150823 = -0.0001371 t
t = 1100 hours
Answer:
1.Metals
These are very hard except sodium
These are malleable and ductile pieces
These are shiny
Electropositive in nature
Non-metals
These are soft except diamond
These are brittle and can break down into pieces
These are non-lustrous except iodine
Electronegative in nature
2. The electrochemical series helps to pick out substances that are good oxidizing agents and those which are good reducing agents.In an electrochemical series the species which are placed above hydrogen are more difficult to be reduced and their standard reduction potential values are negative.
3. Arrhenius theory, theory, introduced in 1887 by the Swedish scientist Svante Arrhenius, that acids are substances that dissociate in water to yield electrically charged atoms or molecules, called ions, one of which is a hydrogen ion (H+), and that bases ionize in water to yield hydroxide ions (OH−).
4. The common application of indicators is the detection of end points of titrations. The colour of an indicator alters when the acidity or the oxidizing strength of the solution, or the concentration of a certain chemical species, reaches a critical range of values.
Answer:
Case 1:
X = Any element from Group I
i) H
ii) Li
iii) Na
iv) K
v) Rb
vi) Cs
Y = 1
Case 2:
X = Any element from Group II
i) Be
ii) Mg
iii) Ca
iv) Sr
v) Ba
vi) Ra
Y = 2
Case 3:
X = Any element from Group III
i) B
ii) Al
iii) Ga
iv) In
v) Ti
Y = 3
Explanation:
The general formula given is as follow,
XCly
So, if X has +1 oxidation state, then it will require only one Cl atom with oxidation number -1 to form a neutral compound, therefore, y = 1.
If X has +2 oxidation state, then it will require two Cl atoms with oxidation number -1 to form a neutral compound, therefore, y = 2.
If X has +3 oxidation state, then it will require three Cl atoms with oxidation number -1 to form a neutral compound, therefore, y = 3.
Answer:
The Electron Configuration for Sulfur(S)= 1s^2 2s^2 2p^6 3s^2 3p^4
Explanation:
Use the sheet attached to help with a future question. (Hint: Follow the red lines). The atomic number will be equal to the number of powers raised.
