Is identical to the nucleus of a normal atomic mass four helium atom i.e. a doubly ionised helium atom
Answer:
<em><u>Rows in the periodic table are called periods</u></em>. As one moves from left to right in a given period, the chemical properties of the elements slowly change. <em><u>Columns in the periodic table are called groups</u></em>. Elements in a given group in the periodic table share many similar chemical and physical properties
Explanation:
Answer:
<u>Homogeneous mixture:</u>
- These are called solutions.
- It has a uniform composition.
- It has only one phase.
- It cannot be separated physically.
- The particles appear smaller in size.
- These are pure substances.
- These are not visible easily visible to the naked eye and also through a microscope.
- Examples include milk, gasoline, sugar solution, corn oil, fog, etc.
<u>Heterogeneous mixture:</u>
- These are called suspensions/colloids.
- It has a non-uniform composition.
- There are two or more phases.
- It can be separated physically.
- The particles are either smaller or larger in size.
- These are not pure substances.
- These are easily visible to the naked eye and also through a microscope
- Examples are- a mixture of mud & water, beach sand, vinegar, air cloud, etc.
Moles of oxygen = mass/molar mass of O2 = 8/31.998 = 0.25 moles.
Number of particles = moles x 6.02 x 10^23 = 0.25 x 6.02 x 10^23 = 1.505 x 10^23 particles.
Hope this helps!
WHILE ARRANGING THE ELEMENTS, NEWLAND OBSERVED THAT ORDER HE SET WERE LIKE NOTES REPRESENTED AS THE SIGNS,THAT IS, EVERY FIRST NOTE IS EQUAL TO THE EIGHT ELEMENT, BUT HE COULD FIND ONLY 58 ELEMENTS THAT WERE CORRECTLY ORDERED IN HIS TABLE