Answer:
Model A
Explanation:
Model A represents an atom that is more reactive than the others represented.
Valence electrons actually determine the reactivity of elements. They also determine the properties of elements.
Elements with one valence electron are highly reactive because they need low energy to remove them. They can either gain more electrons to become stable or they share/give out their electrons.
Therefore, Model A is the correct answer because it has one valence electron and its valence electron is farther from the nucleus thereby this makes it more reactive.
Answer: number of atoms is 5.21 · 10^24
Explanation: Atomic mass of Be is 9.012 g/mol.
Number of moles n = m/M = 78.0 g / 9.012 g/mol =
Multiply this with Avogadro number Na = 6.022*10^23 1/mol
Answer:

Explanation:
Hello,
In this case we use the Boyle's law which allows us to understand the volume-pressure behavior as an inversely proportional relationship:

Whereas we solve for
as the required final pressure:

Best regards.
We have to get the formula of methionine.
The formula of methionine is
Methionine is an essential amino acid of human. It is white crystalline solid.
The formula of methionine is C₅H₁₁NO₂S. Methionine contains five carbon atoms, eleven hydrogen atoms, one nitrogen atom, two oxygen atoms and one sulphur atom.
It contains one amino group (-NH₂) and one carboxylic acid group (-COOH). Atoms are depicted in C-atom in grey, H-atom in ivory, O-atom in red, N-atom in blue and S-atom in yellow.
Answer:
difference between metal and alloy is that the metal is a pure substance whereas the alloy is a mixture of two or more components.
Explanation:
Mostly the metalloids have the appearance just like the metallic appearance And also they are the brittle one's . Boron and silicon are the example. Note; By combining with other metals metalloid can form the alloy