Answer:
Letters
Explanation:
For example, today we use the periodic table which is full of elements named with 1 or 2 letters. Like how Helium is He and Sodium is Na. Hope this helps!!!
<u>Answer:</u>
<u>For 1:</u> Neutralization reaction
<u>For 2: </u>Zinc is more reactive than lead and less reactive than calcium.
<u>Explanation:</u>
When a base reacts with an acid to form a salt and water molecule, it is known as a neutralization reaction. The general equation follows:

The chemical equation for the reaction of calcium hydroxide and nitric acid follows:

A single displacement reaction is defined as the reaction in which a more reactive metal displaces a less reactive metal from its salt solution. The general chemical equation follows:

where,
Metal A is more reactive than metal B
The reactivity of metals is judged by the reactivity series where a metal lying above in the series is more reactive than the metal lying below it.
From the reactivity series below,
Zinc lies above in the series than lead thus is more reactive and will easily replace lead from its aqueous solution.
While zinc lies below in the series than calcium thus is less reactive and will not easily replace calcium from its aqueous solution.


The units of ppm means parts per million. Also, It is equivalent to milligrams per liter. It is one way of expressing concentration of a substance. It u<span>sually used to describe the concentration of something in water or soil. We calculate the mass of CaCO3 as follows:
Mass = 75 mg/L (.050 L) = <span>3.75 mg CaCO3</span></span>
The answer would be B.
U-238 has a n to p ration of 1.6:1. 146 neutrons and 92 protons.
It is actually the most commonly used isotope is reactors.
C-14 is also a radioactive isotope with 8 neutrons and 6 protons.
The usual and ideal n to p ratio is 1:1 such as C-12 or Mg-24
140 g of nitrogen (N₂)
Explanation:
We have the following chemical equation:
N₂ + 3 H₂ -- > 2 NH₃
Now, to find the number of moles of ammonia we use the Avogadro's number:
if 1 mole of ammonia contains 6.022 × 10²³ molecules
then X moles of ammonia contains 6.022 × 10²⁴ molecules
X = (1 × 6.022 × 10²⁴) / 6.022 × 10²³
X = 10 moles of ammonia
Taking in account the chemical reaction we devise the following reasoning:
If 1 mole of nitrogen produces 2 moles of ammonia
then Y moles of nitrogen produces 10 moles of ammonia
Y = (1 × 10) / 2
Y = 5 moles of nitrogen
number of moles = mass / molecular weight
mass = number of moles × molecular weight
mass of nitrogen (N₂) = 5 × 28 = 140 g
Learn more about:
Avogadro's number
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