Answer:
Have the same number of electrons in their outer energy levels
Explanation:
Elements in the same group have similar chemical properties because they have the same number of valence electron(s) in their outermost shell.
Chlorine and Iodine have similar chemical properties because they have the same number of valence electron in their outermost shell. This can be seen from their electronic configuration as shown below:
Cl (17) => 1s² 2s²2p⁶ 3s²3p⁵
I (53) => [Kr] 4d¹⁰ 5s²5p⁵
From the above illustration:
Outer shell of Cl (3s²3p⁵) = 2 + 5 = 7 electrons
Outer shell of I (5s²5p⁵) = 2 + 5 = 7 electrons
Since they have the same number of valence electrons, therefore, they will have similar chemical properties.
<span>The element gold has 32 isotopes, ranging from A =173 to A = 204. during alpha decay Au will loose 2 in atomic number and 4 in mass number . it will form a iridium isotope and helium . according to the above statement, the balanced equation for the alpha decay of gold 173 will be given as below.
173 169 4
79 Au-------------->77 Ir + 2He</span>
The corect answers will be:
1) A
2) B
3) D
Hope this helped :)
Answer:
Percent loss of water = 25%
Explanation:
Given data:
Mass of hydrated salt = 15.6 g
Mass of anhydrous salt = 11.7 g
Percentage of water lost = ?
Solution:
First of all we will calculate the mass of water in hydrated salt.
Mass of water = Mass of hydrated salt - Mass of anhydrous salt
Mass of water = 15.6 g - 11.7 g
Mass of water = 3.9 g
Now we will calculate the percentage.
Percent loss of water = mass of water / total mass × 100
Percent loss of water = 3.9 g/ 15.6 g × 100
Percent loss of water = 25%
Its total charge is zero but for the elements:
Sn===> Sn4+ positive
Cl===> Cl- negative
