Dmitri Mendeleev
<span> Dmitri Mendeleev and Lothar Meyer individually came up with their own periodic law "when the elements are arranged in order of increasing atomic mass,
certain sets of properties recur periodically.</span>
The parent isotope is cobalt-59 (see the picture below).
The mass number is 59 and atomic number is 27 of the parent isotope.
Neutron activation is the process in which atomic nucleus capture free neutron or neutrons.
Cobalt-60 is produced in nuclear reactors in process of neutron activation from parent isotope cobalt-59 (see the picture below).
Atomic number (Z) is total number of protons and mass number (A) is total number of protons and neutrons in a nucleus.
Cobalt-59 and cobalt-60 are the isotopes of chemical element cobalt.
Isotopes are chemical elements with same atomic number (Z), but different mass number (different number of neutrons).
More about isotopes: brainly.com/question/364529
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T₁ = 40°C + 273.15 = 313.15 Kelvin T₂ = 30°C + 273.15 = 303.15 Kelvin
Solving Gay-Lussac's Law for P₁ we get:
P₁ = P₂ • T₁ ÷ T₂ P₁ = 760 torr • 313.15 K ÷ 303.15 K P₁ = 785.07 torr
Using the calculator, we click on the P1 button.
We then enter the 3 numbers 760 313.15 and 303.15 into the correct boxes then click "CALCULATE" and get our answer of 785.07 torr.
Answer:
C.) No. of electrons
Explanation:
A.) is incorrect. The atomic number represents the number of protons in an element. Nitrogen (N) and sodium (Na) always have a differing amount of protons.
B.) is incorrect. The mass number represents the number of protons and neutrons in an element. The number of neutrons and protons are specific to each element (disregarding isotopes). When elements ionize, these amounts are not altered.
C.) is correct. When an element becomes an ion, the number of electrons change. When nitrogen gains 3 electrons and sodium loses 1 electron, they end up having the same number of electrons (10).
D.) is incorrect. When elements ionize, the number of neutrons does not change. The only way two different elements could have the same number of neutrons is if at least one of the elements is an isotope. Isotopes are two or more atoms of the same element that differ in their amounts of neutrons.
