The compound CBr4 has the highest melting point of 91°C
Answer:
Mass of reactant and mass of product must be equal.
Explanation:
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
Explanation:
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In given photosynthesis reaction:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
To determine this, lets use the atomic mass for each element to determine the corresponding number of moles for a given mass of 1 g.
Mo: 95.94 g/mol
1 g/95.94 g/mol = 0.01042 moles Mo
Se: 78.96 g/mol
1 g/78.96 g/mol = 0.01266 moles Se
Na: 22.99 g/mol
1 g/22.99 g/mol = 0.0435 moles Na
Br: 79.9 g/mol
1 g/79.9 g/mol = 0.0125 moles Br
<em>Thus, the answer is Na.</em>
Answer:
B). Allow efficient gathering of unobservable phenomena.
Explanation:
Surveys are described as the method of gathering information from a specified group of respondents for purposes like research or assessment of the truth of thoughts or opinions associated with a process.
As per the question, one of the most considerable benefits of the survey is that 'it allows the efficient gathering of unobservable phenomena'. The data associated with phenomena like stated preferences, behaviors, beliefs, and factual information are unobservable and can not be collected through observation but surveys help in doing so as well as in the assessment of the validity or reliability of the existing propositions about such phenomena. Thus, <u>option B</u> is the correct answer.
Answer:
a. True
Explanation:
From the basic concepts of acids and bases, we know that when a base accepts a hydrogen ion (H⁺), it forms a conjugate acid which can accept again the H⁺ ion:
B⁻ + H₂O ⇆ BH + OH⁻
The stronger the base, the weaker the conjugate base. Thus, as more strength has a base, lesser strength will have the conjugate base (it will not be able to accept again the H⁺ ion). For example, when water (H₂O) loses its H⁺ , it forms the conjugate base OH⁻. So, OH⁻ is the stronger base that can exist in an aqueous solution.
H₂O ⇆ H⁺ + OH⁻
In fact, strong bases are hydroxides, such as NaOH or KOH.
