Answer:
b
Explanation:
A pure substance has a constant composition and cannot be separated into simpler substances by physical means. There are two types of pure substances: elements and compounds.
Answer
No you did not lose weight.
Explanation:
Weight is the force acting on an object, Gravity is a force on earth which does not apply to the moon so your weight may change depending in where you are but your mass will stay the same because mass measures the matter of an object ITSELF! Have a nice day....
The answer is "night sky"
hope i helped :)
Answer:
Increasing atomic number - True
Explanation:
The modern table is based on Mendeleev’s table, except the modern table arranges the elements by increasing atomic number instead of atomic mass.
The Atomic number is the number of protons in an atom, and this number is unique for each element. For example, Hydrogen has an atomic number of 1, Calcium has an atomic number of 20.
In the modern periodic table the elements are further arranged into:
- rows, called periods, in order of increasing atomic number. Elements in the same periods have the same number of shells.
- vertical columns, called groups, where the elements have similar properties. Elements in the same group has the same number of valency (outermost number of electrons)