Answer:
Explanation:
Group one elements are alkali metals. All alkali metal have one valance electron. They loses their one valance electron and from cation with charge of +1.
Charges on group one.
Hydrogen = +1
Lithium = +1
Sodium = +1
Potassium = +1
Rubidium = +1
Cesium = +1
Francium = +1
Group two elements are alkaline earth metals. All alkaline earth metal have two valance electron. They loses their two valance electron and from cation with charge of +2.
Charges on group two.
Beryllium = +2
Magnesium = +2
Calcium = +2
Strontium = +2
Barium= +2
Radium = +2
Group 13 elements are boron family. All elements have three valance electrons. They loses their three valance electron and from cation with charge of +3.
Charges on group 13.
Boron = +3
Aluminium = +3
Gallium = +3
Indium = +3
Thallium= +3
Group 13 elements are also shows +1 charge by losing one valance electron.
<u>Answer:</u> The amount of energy required to convert ammonia back to hydrogen and nitrogen is 45.9 kJ
<u>Explanation:</u>
Endothermic reactions are defined as the reactions in which energy is absorbed in the reaction. The enthalpy change of the reaction is positive.
Exothermic reactions are defined as the reactions in which energy is released in the reaction. The enthalpy change of the reaction is negative.
For the given chemical equation:

In the above reaction, the enthalpy change is negative. So, the reaction is exothermic in nature.
For the reverse reaction, the magnitude of the enthalpy change remains the same but sign for it changes.
Hence, the amount of energy required to convert ammonia back to hydrogen and nitrogen is 45.9 kJ
Answer:
igneous rocks
Explanation:
igneous rocks forms from lava, such as obsidian, basalt, plumice, etc
Answer:
Methods for determining or delivering precise volumes include volumetric pipets and pycnometers; less precise methods include burets, graduated cylinders, and graduated pipets. In this experiment, you will measure masses and volumes to determine density. Four different metal cylinders are investigated.
Explanation:
Explanation:
chemical to add to swimming pools in order
to make the water safer. She mixed two solid
substances together in a sealed container.
The diagram above shows the repeating
groups of atoms that make up the two
starting substances.
After mixing, Tiana found two liquid
substances in the sealed container.
(Nothing had escaped.) Which of the
diagrams to the left shows the repeating
groups of atoms that make up the ending
substances?