Protons-19 because protons are equal to the atomic number which is 19 , electrons-19 electrons are equal to number of protons, neutrons-20 because the mass number of potassium is 39 so subtract 39 from 19 (atomic number) which gives us 20
The correct answer for the blanks is : Primary key field
The primary key field is a place to record data that is unique to each record in the database or file. When you perform your hide duplicate command on primary key field, it will prevent any records from having the same value
The teacher prepares 2.50 liters (l) of a salt solution for a class experiment, in this quantity 2.65 quartz are present.
<h3>What is conversion factor?</h3>
Conversion factor is a quantity which will be multiplied or divide with any other measurement for the conversion of that measurement.
Given that quantity of salt solution = 2.50 L
We know that, 1 L = 1.06 qt
Here conversion factor is 1.06 qt/L as it will be multiplied on given measurement to convert into quartz as:
2.50L = 2.50L × 1.06qt/L = 2.65qt
Hence required value is 2.65qt.
To know more about conversion factor, visit the below link:
brainly.com/question/97386