Answer:
B. materials change their properties.
Explanation:
In a chemical change, materials often change their properties because a re-arrangement of atoms takes place.
A chemical change is one in which new kind of matter is formed.
It is always accompanied by energy changes.
- Chemical changes are not reversible.
- They lead to the production of new kinds of matter
- It involves mass changes
- Requires considerable amount of energy
Answer:
0.66g/mL
Explanation:
La densidad es una propiedad de la materia definida como la masa de una sustancia en un determinado volumen.
En este problema, podemos hallar la densidad sabiendo que la diferencia de masas del pic vacío y el pic lleno es la masa de la solución y que el volumen que ocupa es de 25mL:
<em>Masa solución:</em>
25g - 8.5g = 16.5g
Así, la densidad será:
16.5g / 25mL =
<h3>0.66g/mL</h3>
There are quite a few
relationships between [H+] and [OH−]
ions. And because there is a large range of number between 10 to 10-15
M, the pH is used. pH = -log[H+] and pOH = -log[OH−]. In aqueous solutions, [H+
][OH- ] = 10-14. From here we can derive the values of each concentration.
-log[H+ ] + -log[OH- ] = -log[10-14]
pH + pOH = 14
So pH = 14 – pOH and pOH = 14 –
pH
Answer:
If an object falls from one point to another point inside a gravitational field, the force of gravity will do positive work on the object, and the gravitational potential energy will decrease by the same amount
