(A) nervous, muscular, skeletal
Answer:
The number of electrons in the outermost shell of an element is represented in the periodic table as the group number that element is situated in the number of electrons in all shells of an element is represented in the periodic table as the element's atomic number.
Explanation:
I hope that helps
The "sea of instability" refers to a region of elements on the periodic table that are highly unstable. These elements have extremely short half-lives that may be measured in micro- or nanoseconds. (A nanosecond is the time it takes for light to travel one foot.) This region of unstable elements surrounds the island of stability.
Answer:
Density, melting point. and magnetic properties
Explanation:
I can think of three ways.
1. Density
The density of Cu₂S is 5.6 g/cm³; that of CuS is 4.76 g/cm³.
It should be possible to distinguish these even with high school equipment.
2. Melting point
Cu₂S melts at 1130 °C (yellowish-red); CuS decomposes at 500 °C (faint red).
A Bunsen burner can easily reach these temperatures.
3. Magnetic properties
You can use a Gouy balance to measure the magnetic susceptibilities.
In Cu₂S the Cu⁺ ion has a d¹⁰ electron configuration, so all the electrons are paired and the solid is diamagnetic.
In CuS the Cu²⁺ ion has a d⁹ electron configuration, so all there is an unpaired electron and the solid is paramagnetic.
A sample of Cu₂S will be repelled by the magnetic field and show a decrease in weight.
A sample of CuS will be attracted by the magnetic field and show an increase in weight.
In the picture below, you can see the sample partially suspended between the poles of an electromagnet.
The answer would be D. because when an acid and base mix the start to cancel each other out causing it to neutralize