Which of the following statements is/are correct? I.
II.
Mass of 1 atom of Carbon-12 is equal to 1 amu
Mass of 4 atoms of Carbon-12 is equal to mass of 3 atoms of Oxygen-16
(A) Only I
(B) Only II
(C) Both I and II
(D) None of them

The correct statement is;

(B) Only II

Explanation:

I) The atomic mass unit or amu which is also known as daltons which is defined as 1/12 × the mass of a carbon-12 atom, which is therefore, 1.660538921 × ⁻²⁴ grams

Therefore, the mass of 1 atom of carbon-12 = 12 amu

II) The mass of one mole of oxygen-16 is 16 grams while the mass of one mole of carbon-12 is 12 grams

The mass of 4 atoms of carbon 12 = 4 × 12 amu = 48 amu

The mass of 1 atom of oxygen-16 = 15.99491461956 amu

Therefore, the mass of 3 atoms of oxygen-16 = 3 × 15.99491461956 = 47.9847438587 amu ≈ 48 amu

Therefore only II is correct.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?