A test tube becomes cool to the touch.
Explanation:
The signs for an endothermic reaction would most likely be that a test tube becomes cool to touch. An endothermic reaction is a reaction in which heat is absorbed from the environment.
- At the end of this heat change, the surrounding becomes colder.
- Most endothermic reactions are always shown by the test tube becoming colder.
- For exothermic reaction in which heat is given off to the surroundings, the tube should be hotter.
Learn more:
Exothermic reactions brainly.com/question/10567109
#learnwithBrainly
There is no picture hunny. Please add a picture please boo.
The answer is the first: that structural models provide minimal three-dimensional information. This is because the ball-and-stick model cannot show the actual size of the atoms depicted in the model. You also cannot see the actual bond lengths between the atoms. This, then, limits the accuracy of the model and fails to precisely portray how the chemical compounds being shown are like in all actuality. Thus, though you do see a three-dimensional picture of the chemical compound, this picture is not completely accurate and is not scaled to size.
Answer:
Explanation: Nickel is element number 28 on the period table with a mass number 58 or 60, it exist in two forms and the phenomenon is known as isotopy
Definition of Isotopy is simply a phenomenon whereby elements exist in various forms that have the exact same chemical properties but different atomic mass.
58-Ni has atomic number 28 because that's the number o the element on the periodic table. Proton number is the same as atomic number and same as electron number for a neutral element or element without charge.
Mass number = Proton number (P) + Neutron number (N)
58 = 28 + N
N= 58-28
N= 30
58-Ni has 28 has the atomic number, proton number and electron number because it is a neutral atom but the neutron is 30 as shown in the calculation above.
60-NI+2 has a contrasting figure because the element has a charge of +2
Mass number= Proton + Neutron
60 = 28 + N
N= 60 - 28
N= 32
Electron = Proton - Charge
28 - (+2)
28 - 2
Electron = 26
The number of electron in 60-Ni +2 differs from 58-Ni because of the number of charge
Electron number differs from proton number in any element with a charge.
