Answer:
answer is b
Explanation:
All elements in a row have the same number of electron shells. Each next element in a period has one more proton and is less metallic than its predecessor
The purpose of using distilled water in the cuvette of the spectrophotometer is to calibrate the instrument. It is generally considered that distilled water shows zero absorbance and 100 % transmittance. So, to zero out the absorbance of compounds other than the analyte being determined, distilled water is used as a blank.
If the unknown being determined is prepared using ethanol as the base solution, the blank used must be ethanol. This is because absorbance if any from the solvent, ethanol must be zeroed out as when the measurement of the actual unknown is being made, the absorbance of the solvent does not interfere.
Answer:
Explanation:
Empirical formula of ionic compound formed by two ions 
and 
is 
(for 
) of AB (for x = y)
The above empirical formula is in accordance with charge neutrality principle
Here each cation (
and 
) can form two ionic compounds by combining with two given anions (
and 
).
So the four ionic compounds are:
Melting, vaporization, boiling, and sublimation.
If the half-life of a sample of a radioactive substance is 30 seconds, how much would be left after 60 seconds? <span>
A. one-fourth</span>
