Norepinephrine<span> (</span>NE<span>), also called </span>noradrenaline<span> (</span>NA<span>) or </span>noradrenalin<span>, is an </span>organic chemical<span> in the </span>catecholamine<span> family that functions in the </span>brain<span> and </span>body<span> as a </span>hormone<span> and </span>neurotransmitter. The name "noradrenaline," derived from Latin roots meaning "at/alongside the kidneys," is more commonly used in the United Kingdom; in the United States, "norepinephrine," derived from Greek roots having that same meaning, is usually preferred.<span> "Norepinephrine" is also the </span>international nonproprietary name<span> given to the </span>drug.<span>Regardless of which name is used for the substance itself, parts of the body that produce or are affected by it are referred to as </span>noradrenergic<span>.</span>
Probably b because soil can’t be the exact same and so that cancels out a and d
Standard temperature is 273 K
Standard pressure is 1 atm
We use the ideal gas equation to find out density of nitrogen gas in g/L
Ideal gas equation:

Molar mass of 
Pressure = 1 atm
Temperature = 273 K

= 1.25 g/L
Therefore, density of nitrogen gas at STP is 1.25 g/L
<h3>Answer:</h3>
Strontium (Sr)
<h3>Explanation:</h3>
The condition given in statement is the presence of two valence electron. Hence, first we found the electronic configuration of given atoms as follow;
Rubidium [Kr] 5s¹
Strontium [Kr] 5s²
Zirconium [Kr] 4d² 5s²
Silver [Kr] 4d¹⁰ 5s¹
From above configurations it is cleared that only Strontium and Zirconium has two electrons in its valence shell.
We also know that s-block elements are more reactive than transition elements due to less shielding effect in transition elements hence, making it difficult for transition metals to loose electrons as compared to s-block elements. Therefore, we can conclude that Strontium present in s-block with two valence electrons is the correct answer.
Answer:
A calorimeter is an apparatus for measuring the amount of heat involved in a chemical reaction or other process.