For the first question, salt is soluble while sand is insoluble or not dissolvable in water. The salt should have vanished or melted, but the sand stayed noticeable or visible, making a dark brown solution probably with some sand particles caught on the walls of the container when the boiling water was put in to the mixture of salt and sand. The solubility of a chemical can be disturbed by temperature, and in the case of salt in water, the hot temperature of the boiling water enhanced the salt's capability to melt in it.
For the second question, the melted or dissolved salt should have easily made its way through the filter paper and into the second container, while the undissolved and muddy sand particles is caught on the filter paper. The size of the pores of the filter paper didn’t change. On the contrary, the size of the salt became smaller because it has been dissolved which is also the reason why it was able to go through the filter paper, while the size of the sand may have doubled or even tripled which made it harder to pass through.
Answer:
They have all the same number of protons and electrons ( 6)
Explanation:
Carbon 12, Carbon 13 and Carbon 14 are all isotopes of Carbon.
The definition of an isotope is: They have the same number of protons (and electrons), but a different number of neutrons. Different isotopes of the same element have different masses.
Carbon 12 means an isotope with mass 12 u
it has 6 protons,(and 6 electrons) and 6 neutrons : 6 neutrons + 6 protons = 12
Carbon 13 is an isotope with mass 13 u
It has the same amount of protons ( and electrons) as Carbon 12, so 6 protons and 6 electrons
13 - 6 = 7 ⇒ Carbon 13 has 7 neutrons
Carbon 14 is an isotope with mass 14
it has the same of protons ( and electrons) as Carbon 12 and Carbon 13, so 6 protons and 6 electrons
14 - 6 = 8 ⇒ Carbon 14 has 8 neutrons
We can conclude that Carbon 12, Carbon 13 and Carbon 14 are 3 isotopes of Carbon. They all have the same number of protons (and electrons) = 6.
This means the isotopes will also have the same atomic number, because they are all isotopes of the same element.
This one is easy. It's just addition and subtraction. Add the partial pressure of Argon and the partial pressure of Helium:
152 kPa
<u>+305 kPa</u><u>
</u> 457 kPa
Next, subtract the result from the total pressure:
1015 kPa
<u>- 457 kPa</u>
558 kPa
Regard the principle of utilization of two gas.
Make a consistent control of hardware containing gas.
Make a consistent control of weight diminishing valves giving gas.
No smoking zone.
Answer:
Explanation:
Copper(II) ion Iron and copper are an examples of transition metals, which are most likely to form anions with a change of -1.
The transition elements are metals that form cations when they react but the situation is a bit more complex. Many transition elements are able to form more than one cation because they have a partially filled d-subshell that is just slightly lower in energy than the outer s subshell. When a transition metal forms a positive ion, it always loses electrons from its outer s subshell first. Once these are gone, any further electron loss takes place from the partially filled d subshell. Iron is a typical example.
Its electron configuration is Fe [Ar]3d⁶4s²
When iron reacts, it loses its 4s electrons fairly easily to give Fe²⁺. But because the 3d subshell is close in energy to the 4s, it is not very difficult to remove still another electron to give Fe³⁺.
Fe³⁺ [Ar]3d⁵
Because so many transition elements are able to form ions in a similar way, the ability to form more than one positive ion is usually cited as one of the characteristic properties of the transition elements. Frequently, one of the ions formed has a 2+ charge, which arises from the loss of the outer two s electrons. Ions with larger positive charges result when additional d electrons are lost.
