Answer:
The period 4 alkaline-earth metal has the name Calcium. An isotope of this element having 20 neutrons has a mass number of 40.
Explanation:
Looking at the periodic table 4th row for the alkaline-earth metal, we can find Calcium which has an atomic number of 20 (or protons number, or z). The mass number is given by the sum of protons and neutrons. If the number of protons in this case is 20 and the number of neutrons is also 20, the mass number A = 40.
A because A is the only answer
Methanoic acid has a molecular formula of HCOOH, when form an ester it's HCOO-, so the rest of the ester is -C4H9, a saturated 4 carbon chain. As shown in the attached diagram, there are 4 structural isomers, and the third isomer has 2 stereoisomers. So the answers is D:5.
Answer:
The amount of heat required to melt 25 grams of ice is 8,350 Joules or 2,000 calories.
Explanation:
