Ceres is a dwarf planet, so A.
Answer: Option (c) is the correct answer.
Explanation:
A positron is denoted as
, a neutron is denoted as
, an electron is denoted as
, and a proton is denoted as
.
Therefore, when
will decay into
this means there occurs decrease in its mass number. Hence, it means a neutron will be releasing during this reaction.
The reaction will be as follows.

Answer:
False.
Explanation:
Hello.
In this case since sodium is a soft brilliant metal and chlorine is a green gas at normal conditions, they have totally different properties. Thus, since sodium chloride is also known as the table salt which is present as white crystals we can infer that the compound does not have the same properties, therefore it is false.
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Answer:
atoms of 40K
Explanation:
You can use the molecular mass and the Avogadro´s number, in the following formula:

where
is the sample mass,
is the molecular mass of the KCl and IA(40K) is the isotopic abundance of 40K.
Now replacing the values, you can find:


Answer:
Physical changes
Explanation:
Changes in the state of matter are physical changes.
First, the material is made up of the same components that is was before it changed states.
The physical properties of the material changed, but its chemical composition did not, meaning that is is a physical change.