91影视

In what way are isotopes of a given element always different? In what way(s) are they always the same?

Write the symbol for each of the following ions: (a) the ion with a \(1 + \) charge, atomic number \(55,\) and mass number \(133\)(b) the ion with \(54\) electrons, \(53\) protons, and \(74\) neutrons (c) the ion with atomic number\(15,\) mass number \(31,\) and a \(3 - \) charge (d) the ion with \(24\) electrons, \(30\) neutrons, and a \(3 + \)charge

Open theBuild an Atom simulation (http://openstaxcollege.org/l/16PhetAtomBld)and click on the

Atom icon.

State the numbers of protons, neutrons, and electrons in your atom, as well as the net charge and mass number.

Open theBuild an Atom simulation (http://openstaxcollege.org/l/16PhetAtomBld)(a) Drag protons, neutrons, and electrons onto the atom template to make a neutral atom of Oxygen-16 and give theisotope symbol for this atom.(b) Now add two more electrons to make an ion and give the symbol for the ion you have created.

Determine the number of protons, neutrons, and electrons in the following isotopes that are used in medical diagnoses:

(a) atomic number 9_, mass number 18_, charge of 1^-

b) atomic number 43, mass number 99, charge of 7⁺

(c) atomic number 53, atomic mass number 131, charge of 1^-

(d) atomic number 81, atomic mass number 201, charge of 1⁺

(e) Name the elements in parts (a), (b), (c), and (d)

Give the number of protons, electrons, and neutrons in neutral atoms of each of the following isotopes:

\(\begin{aligned}{}\begin{aligned}{{}{}}{\left( a \right){\rm{ }}{}_5^{10}B}\\{\left( b \right){\rm{ }}{}_{80}^{199}Hg}\\{\left( c \right){\rm{ }}{}_{29}^{63}Cu}\\{\left( d \right){\rm{ }}{}_6^{13}C}\end{aligned}\\\left( e \right){\rm{ }}{}_{34}^{77}Se\end{aligned}\)

Give the number of protons, electrons, and neutrons in neutral atoms of each of the following isotopes:\(\begin{aligned}{}\left( a \right){\rm{ }}{}_3^7Li{\rm{ }}\\\left( b \right){\rm{ }}{}_{52}^{125}Te{\rm{ }}\\\left( c \right){\rm{ }}{}_{47}^{109}Ag{\rm{ }}\\\left( d \right){\rm{ }}{}_7^{15}N{\rm{ }}\\\left( e \right){\rm{ }}{}_{15}^{31}P\end{aligned}\)

In the following drawing, the green spheres represent atoms of a certain element. The purple spheres represent atoms of another element. If the spheres of different elements touch, they are part of a single unit of a compound. The following chemical change represented by these spheres may violate one of the ideas of Dalton鈥檚 atomic theory. Which one?

Click on the site (http://openstaxcollege.org/l/16PhetAtomMass) and select the 鈥淢ix Isotopes鈥� tab, hide the 鈥淧ercent Composition鈥� and 鈥淎verage Atomic Mass鈥� boxes, and then select the element boron.

(a) Write the symbols of the isotopes of boron that are shown as naturally occurring in significant amounts.

(b) Predict the relative amounts (percentages) of these boron isotopes found in nature. Explain the reasoning behind your choice.

(c) Add isotopes to the black box to make a mixture that matches your prediction in (b). You may drag isotopes fromtheir bins or click on 鈥淢ore鈥� and then move the sliders to the appropriate amounts.

(d) Reveal the 鈥淧ercent Composition鈥� and 鈥淎verage Atomic Mass鈥� boxes. How well does your mixture match withyour prediction? If necessary, adjust the isotope amounts to match your prediction.

(e) Select 鈥淣ature鈥檚鈥� mix of isotopes and compare it to your prediction. How well does your prediction comparewith the naturally occurring mixture? Explain. If necessary, adjust your amounts to make them match 鈥淣ature鈥檚鈥漚mounts as closely as possible.

In the following drawing, the green spheres represent atoms of a certain element. The purple spheres represent atoms of another element. If the spheres touch, they are part of a single unit of a compound. Does the following chemical change represented by these symbols violate any of the ideas of Dalton鈥檚 atomic Theory? If so, which one?