10g
Explanation:
Box 1, Mass of A = 10g
Box 2, Mass of B = 5g
Box 3, = 1A + 1B
Unknown:
Mass of B that would combine with mass of 20g of A
Solution:
Mass ratio of A to B:
= mass ratio
= mass ratio
The mass ratio of A to B = 2: 1
Now, number of B that will combine with 20g of A;
= mass ratio
= 
Mass of B = 10g
10g of B would combine with 20g of A
learn more:
Rate brainly.com/question/8677367
#learnwithBrainly
ANSWER
2 valence electrons
STEP-BY-STEP EXPLANATION:
The electronic configuration is given below as

Looking at the configuration, you will see that the last energy carries 2 electrons
Hence, the valence electrons are 2
Answer:
Probably stop taking the prescribed durg and contact your pharmacist and your doctor that gave you your prescription asap.
Explanation:
Both of those health professionals will assist the patient in understanding how to go about the next steps for side effect relief.