atoms are made of 3 types of subatomic particles; electrons, protons and neutrons
atomic number is the number of protons. atomic number is characteristic for the element. In ground state atoms, the number of electrons and protons are the same.
the electronic configuration of Ca in the ground state is
Ca - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
when Ca loses its 2 valence electrons, it becomes positively charged and the electronic configuration becomes
Ca - 1s² 2s² 2p⁶ 3s² 3p⁶
number of electrons in Ca²⁺ is 18
the atom in the ground state would have the same number of electrons and protons. Therefore number of protons are 18. then the atomic number of the element is 18
the atom having an atomic number of 18 is Ar.
the answer is 1) Ar
Answer:
118
Explanation:
Of these 118 elements, 94 occur naturally on Earth. Six of these occur in extreme trace quantities: technetium, atomic number 43; promethium, number 61; astatine, number 85; francium, number 87; neptunium, number 93; and plutonium, number 94.
Explanation:
As it is known that there are two types of properties. These are extensive and intensive.
Extensive properties : Properties that depend on the size or amount of system. For example, mass, volume etc.
Intensive properties : Properties that do not depend on the size or amount of system. For example, density, melting point, specific heat capacity etc.
On the basis of these properties water and ethanol are distinguished as follows.
- Density of water is 997 kg/
whereas density of ethanol is 789 kg/. Both these liquids can be separated by intensive properties. - Melting point of water is zero degree celsius whereas melting point of ethanol is -114.1 degree celsius.
- Specific heat capacity of water is 4.184
whereas specific heat capacity of ethanol is 2.46 . - Mass of the given liquids cannot be differentiated because they will keep on changing depending on the quantity required. As mass is an extensive property, therefore, it is difficult to differentiate between the two liquids.
Thus, we can conclude that properties like density, melting point, specific heat capacity can help a chemist distinguish between ethanol and water.
The letter (d.) strong base or acid would be the most appropriate answer to the question above. An indicator is a strong base or acid. Indicators are strong base and acid because through this you can determine if a compound is acid or base with its color.
