Answer:
a. The student performed the splint test incorrectly. He should of observed a popping sound when the splint was placed in the test tube.
Explanation:
It is given that a student performed an experiment where he dropped a nickel metal in to HCl solution. He observed the reaction and performed a splint test in the test tube that is filled with a gas which is formed while Nickle is dropped into the solution of HCl.
But the experiment that the student performed was incorrect. He must have observed the popping sound when the splint was placed in the test tube.
When the splint was added to the gas splint flared up. The hydrogen gas pops out when exposed to the flame.
![$Ni + HCl(aq) = NiCl + H_2$](https://tex.z-dn.net/?f=%24Ni%20%2B%20HCl%28aq%29%20%3D%20NiCl%20%2B%20H_2%24)
Thus the correct option is (a).
Answer:
the mass number decreases by 4 and the atomic number decreases by 2
False
Although we use many of their ideas to describe atoms today, such as the existence of a tiny, dense nucleus in an atom (proposed by Rutherford), or the notion that all atoms of an element are identical (proposed by Dalton), some of their ideas have been rejected by the modern theory of the atom.
For example, Thompson came up with the plum pudding model to describe an atom, which resembled a sphere of positive charge with electrons embedded in it. We know now, however, that atoms are mostly empty space with a tiny, dense nucleus.
Another example is Dalton's atomic theory, which stated that atoms are indivisible particles. However, this was disproved by the discovery of subatomic particles.
A bright feild is most commonly used
Explanation:
Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. ... Electric charge is carried by subatomic particles. In ordinary matter, negativecharge is carried by electrons, and positive charge is carried by the protons in the nuclei of atoms.
Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of electric charge: positive and negative (commonly carried by protons and electrons respectively). Like charges repel and unlike attract. An object with an absence of net charge is referred to as neutral. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate for problems that do not require consideration of quantum effects.