Based on the trend of electronegativities values of the elements <em>Be, Mg, Ca, </em>and,<em> Sr</em> within their group (increasing from bottom to top), the atoms of the element Sr will have the <u>least attraction</u> for an electron.
We need to remember that electronegativity indicates the affinity or attraction of an element for an electron. Hence, the <u>higher</u> the <em>electronegativity,</em> the<u> higher</u> the <em>attraction </em>of that element for an <em>electron</em>.
The values of <em>electronegativities </em>of the given <em>elements </em>are the following:
Be = 1.57
Mg = 1.31
Ca = 1.0
Sr = 0.95
We can see that the increasing trend of <em>electronegativities </em>in this group is from the <u>bottom to the top</u>, having the Sr with the lowest electronegativity value and the <em>Be</em> with the <em>highest</em>.
This trend is related to atomic size, the <u>larger</u> the <em>atomic size</em>, the <u>lower</u> the <em>electronegativity</em> because the <em>electron </em>in the outermost shell will feel <u>less attraction</u> towards the nucleus of an atom. In a group of the periodic table, the <em>size </em>of an <em>atom </em>will <em>increase </em>from <u>top to bottom</u>.
Therefore, according to the said above, the atoms of the Sr will have the least attraction for an electron (it has the lower electronegativity value).
Find more about electronegativity here:
I hope it helps you!
Sn(s) + 2 HF(aq) ----> SnF2(s) + H2(g)
M HF = 20 g/mol
M SnF2 = 157 g/mol
40 g (HF) -----> 157 g (SnF2)
30 g (HF) -----> x g (SnF2)
x = 30 g × 157 g / 40 g = 117,75g
Answer: 117,75 g
:-) ;-)
Answer:
Explanation:
Solubility is s.
s 2s
When we have Ca(OH)2 in Na(OH) solution, because NaOH has OH- also :
,
because 2s << 0.047,
we can write
Answer:
The density of the nugget is 19.3g/cm³
It is gold because all samples of gold will have the same density value
You should buy it.
Explanation:
Given parameters:
Density of gold = 19.3g/cm³
Length on all sides = 5cm
Mass in kg = 2.413kg
Unknown:
Density = ?
Is it gold = ?
Should you buy it = ?
Solution:
To solve this problem, we need to find the density of the nugget first.
Density =
Mass = 2.413kg
We need to convert to g:
1kg = 1000g
2.413kg = 2413g
Volume = L³ = 5³ = 125cm³
Therefore;
Density = = 19.3g/cm³
The density of the nugget is 19.3g/cm³
It is gold because all samples of gold will have the same density value
You should buy it.
Answer: 2.00 V
Explanation:
The balanced redox reaction is:
Here Al undergoes oxidation by loss of electrons, thus act as anode. Copper undergoes reduction by gain of electrons and thus act as cathode.
Where both are standard reduction potentials.
Thus the standard cell potential is 2.00 V