Answer:
Explanation:
Lewis dot structures represent the symbol of an atom we're looking at and the number of valence electrons it has. This number is represented by the sum of dots around the symbol.
- Potassium is in group 1A, this means it only has one valence electron, so we draw K with one dot in its Lewis diagram;
- Argon is in group 8A, this means it has eight valence electrons, so we draw Ar with 8 dots around it in its Lewis diagram;
- Silicon is in group 4A, this means it has four valence electrons, so we draw Si with 4 dots around it in its Lewis diagram;
- Arsenic is in group 5A, this means it has five valence electrons, so we draw As with 5 dots around it in its Lewis diagram.
Those are represented in the image attached below:
Answer:
Considering the half-life of 10,000 years, after 20,000 years we will have a fourth of the remaining amount.
Explanation:
The half-time is the time a radioisotope takes to decay and lose half of its mass. Therefore, we can make the following scheme to know the amount remaining after a period of time:
Time_________________ Amount
t=0_____________________x
t=10,000 years____________x/2
t=20,000 years___________x/4
During the first 10,000 years the radioisotope lost half of its mass. After 10,000 years more (which means 2 half-lives), the remaining amount also lost half of its mass. Therefore, after 20,000 years, the we will have a fourth of the initial amount.
Answer:
I think it is 860 g MG Cl2
Explanation:
your welcome
Answer:
Explanation:
A reaction is spontaneous at all temperatures by the following combinations:
=> A negative enthalpy change ( 
)
=> A positive entropy change ( 
)
See the attached file for more better understanding!
Answer:
589.8 kJ/mol
Explanation:
Let's consider the process in which <em>the most loosely bound electron from each atom in a mole atom of gaseous calcium is removed.</em>
Ca(g) + Energy ⇒ Ca¹⁺(g) + 1 e⁻
The energy involved in this process is known as First Ionization Energy. The First Ionization Energy for calcium is 589.8 kJ/mol.
