4
Numbers above zero are significant, as well as any zeros that appear in between two non-zero numbers.
When a substance is undergoing a change of state, the heat that is been added to the substance at that particular point in time is used to work on the chemical bonds that is holding the molecules of the substance together; the heat is not used to increase the temperature of the substance at that particular point. For instance, in the case of ice, at its melting point the heat supplied is used to break the inter molecular force that is holding the particles of the ice together. When the bonds are completely broken and the ice has to liquid then the temperature of the water will increase.
Answer:
A) One that occurs on its own
Answer:
Negative; positive
Explanation:
Whenever we have an ionic substance, by convention, we firstly write a symbol of a metal we have. Metals tend to lose their electrons to make ionic compounds and become positively charged species, also known as cations.
Similarly, the metal cation in an ionic substance is followed by a nonmetal. Nonmetal atoms tend to gain the electrons lost by the metals in order to become negatively charged species, also known as anions.
That said, at the front of the compound we have a cation with the positive charge and at the back of the compound we have an anion with the negative charge.
Answer:
The concentration of the resulting solution is 0.25 or one quarter of the standard solution
Explanation:
Whereby the molar concentration of the standard solution is P molar per liter, we have
25 ml of the standard solution contains
25/1000×P moles of the standard solution such that the resultant solution has a volume of 25 + 75 = 100 ml contains 0.025 P moles of the standard solution
The concentration of a solution is the number of moles contained per liter, which gives
100 ml contains 0.025 P moles
1 liter = 1000 ml will contain 1000/100 × 0.025 = 0.25 P moles of the stanard solution
Therefore, the concentration of the resulting solution is 0.25 or one quarter of the standard solution.
