Answer:
When you heat ice, the individual molecules gain kinetic energy, but until the temperature reaches the melting point, they don't have energy to break the bonds that hold them in a crystal structure. They vibrate more quickly within their confines as you add heat, and the temperature of the ice goes up.
Answer:
cells arose from preexisting cells
Explanation:
<em>Rudolph Virchow is a German biologist that built on the work of other scientists such as Theodor Schwan to contribute his own quota to the development of the cell theory as it is currently known.</em>
After several studies, Virchow rejected the idea of spontaneous generation and accepted the initially rejected idea of cell division. He earlier believed that cell division only takes place is some special type of cells and not in all cells.
Even though Virchow was not the first to bring the idea of cells arising from preexisting cells, he was the one that popularized the idea and added it to the earlier belief that all living organisms are made up of cells.
Answer: The reaction is endothermic.
Explanation:
Endothermic reaction : It is a type of chemical reaction where the energy is absorbed from the surrounding. In the endothermic reaction, the reactant have less energy than the energy of products
In endothermic reaction, enthalpy terms is located on the reactant side.
Example: 
Exothermic reaction : It is a type of chemical reaction where the energy is released into the surrounding. In the exothermic reaction, the energy of reactants are more than the energy of products
In exothermic reaction, enthalpy terms is located on the product side.
Example: 
Answer:
did not understand a thing
Answer:
Mass = 7.2 g
Explanation:
Given data:
Mass of water produced = ?
Mass of oxygen = 7.8 g
Solution:
Chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of oxygen:
Number of moles = mass/ molar mass
Number of moles = 7.8 g/ 32 g/mol
Number of moles = 0.2 mol
Now we will compare the moles of water with oxygen.
O₂ : H₂O
1 : 2
0.2 : 2×0.2 = 0.4 mol
Mass of water:
Mass = number of moles × number of moles
Mass = 0.4 mol × 18 g/mol
Mass = 7.2 g
