D) Radioactive contamination
Answer: There are four atoms
Explanation: mass of Cl atom is 35.45 amu
Amount of atoms n = m/M = 142 / 35.45 = 4
P1 * V1 ÷ T1 = P2 * V2 ÷ T2
45 * 1.20 ÷ 314 = 96 * V2 ÷ 420
30,144 * V2 = 22,680
V2 = 22,680 ÷ 30,144
The new volume is approximately 0.75 liter.
I hope I helped
the formation of cations by using electron dot structures are :
a) Al
.
Al . losing the three valence electrons makes the Al³⁺
.
b) Sr :
Sr : losing the two valence electrons makes Sr²⁺
c) Ba
: Ba , losing the two valence electrons makes it Ba²⁺
A Lewis electron dot diagram is a representation of the valence electrons of an atom that employments specks around the image of the element. The number of dots equals the number of valence electrons within the molecule. These dots are arranged to the right and left and over and underneath the symbol, with no more than two dots on a side. Cations are the positive ions shaped by the loss of one or more electrons. The foremost commonly shaped cations of the representative elements are those that include the loss of all of the valence electrons.
To know more about the lewis electron dot diagram refer to the link brainly.com/question/14191114?referrer=searchResults.
#SPJ9
Answer: D. 19.9 g hydrogen remains.
Explanation:
To calculate the moles, we use the equation:
a) moles of 
b) moles of 
According to stoichiometry :
1 mole of require 1 mole of
Thus 0.0787 moles of 
require=
of
Thus is the limiting reagent as it limits the formation of product and acts as the excess reagent. (10.0-0.0787)= 9.92 moles of are left unreacted.
Mass of 
Thus 19.9 g of remains unreacted.
