Answer:
The number of electrons in the outermost shell of an atom determines its reactivity. Noble gases have low reactivity because they have full electron shells. Halogens are highly reactive because they readily gain an electron to fill their outermost shell.
Explanation:
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Answer:
30, 50
Explanation:
Hello,
In this since an element's atomic number is equal to the number of protons in its atom, we can infer that selenium's atomic number is 30. Moreover, due to the fact the the neutrons are equal to the atomic mass minus the atomic number or the number of protons, by knowing the number of neutrons we compute the atomic as follows:

Thus, answer is 30, 50.
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Answer:
A la izquierda el catión y a la derecha el anión.
Explanation:
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En este caso, y basado en las normas IUPAC para la escritura de las fórmulas moleculares, es necesario primero escribir el catión a la izquerda, seguido del anión a la derecha, tal y como se muestra en los siguientes ejemplos, recordando que el catión es el ion cargado positivamente y el anión, negativamente:

Los cuales son cloruro de potasio y sulfato de plata respectivamente. También es necesario tener en cuenta que los metales tienden a ser cationes por su capacidad de perder electrones, mientras que los no metales a ganarlos y por ende resultar como aniones.
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The best and most correct answer among the choices provided by your question is the first choice or letter A "<span>The chemical bonds of the products have more energy than the chemical bonds of the reactants."
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The term endothermic<span> process describes a process or </span>reaction<span> in which the system absorbs energy from its surroundings; usually, but not always, in the form of heat.</span>
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Answer:
yes
Explanation:
yes because the ice changes forms physically and can be changed back. not 100% sure tho