Answer:
28
Explanation:
it states that the atom is neutral, meaning the number of electrons and protons are the same. so if there are 13 electrons, there are 13 protons. And the mass number is neutrons plus protons. So 13+15 is 28
If the potassium atoms could be lined up in a row, it would take to make a 1.00 ft row of potassium atoms is 5.45 × 10⁻⁸.
Potassium atom is represented by K with atomic number 19. It is a silvery white metal.
Given,
Radius = 280pm = 280 × 10⁻¹²m
Diameter = 2radius = 560× 10⁻¹²m = 560pm
We know that,
1 feet = 0.305m
So, number of potassium atoms that fits into the row,
1 feet = 0.305/560 × 10⁻¹²
1 feet = 5.45 × 10⁻⁸
Hence, it takes 5.45 × 10⁻⁸ atoms of potassium to make a 1 feet row.
Learn more about Potassium here, brainly.com/question/13321031
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Answer:
495 pm (see the relationship between the edge length (a) and radius (r) of atoms in attachment).
Explanation:
A <em>crystalline solid</em><em> possess rigid and long-range order; its atoms, molecules, or ions occupy specific positions</em>. A <em>unit cell</em><em> is the basic repeating structural unit of a crystalline solid</em>. Each sphere in the unit cell represents an atom, ion, or molecule and is called a <em>lattice point</em>. <u>The way the spheres are arranged in layers determines what type of unit cell we have.</u>
In the face-centered cubic cell, there are <u>spheres at the center of each of the six faces of the cube</u>, in addition to the eight corner spheres (see the second picture in the attachment). Each sphere in this arrangement is said to have a coordination number of 12 since each sphere is in contact with six spheres in its own layer, three spheres in the layer above, and three spheres in the layer below. The <em>coordination number</em><em> is defined as the number of atoms (or ions) surrounding an atom (or ion) in a crystal lattice</em>.
In the first picture in the attachment we can see that the relationship between the atomic radius <em>r</em> and the edge length <em>a</em> face-centered cubic cell is:
a=√8*r
Therefore, the edge length will be √8*175 pm = 495 pm
Answer:Oxygen
Explanation:
Oxygen gets reduced when iron is oxidized.
Answer:
These systems are defined both by the types of energy and matter they contain and by how that matter and energy move through and between systems. In natural systems, both energy and matter are conserved within a system. This means that energy and matter can change forms but cannot be created or destroyed.
Explanation: