Answer:
Phosphorous has the smallest atomic size.
Explanation:
As we know these elements belong to same period means there valence shell is the same. So moving from left to right along the period the shell number remains constant but the number of protons and electrons increases. So, due to increase in number of protons the nuclear charge increases hence attracts the valence electrons more effectively resulting in the decrease of atomic size.
Elements and their atomic radius are as follow,
<span><span>Magnesium 0.160 nm
</span><span>
Aluminium 0.130 nm
</span><span>
Silicon 0.118 nm
</span><span>
Phosphorus <span>0.110 nm</span></span></span>
The daughter isotope (a decay product)of O-15 = N-15(Nitrogen 15)
<h3>Further explanation
</h3>
Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
- alpha α particles ₂He⁴
- beta β ₋₁e⁰ particles
- gamma particles γ
- positron particles ₁e⁰
O-15 emits positron particles ₁e⁰, so the atomic number decreases by 1, the mass number is the same
Reaction

The mass number of the daughter isotope = 15, atomic number = 7
If we look at the periodic system, the element with atomic number 7 is Nitrogen (N)
Answer:
4)experiments with cathode ray tubes
Explanation:
when sufficiently high voltage is applied across the electrods, current starts flowing through a stream of particles moving in the tube the negative electrode (cathode) to the positive electrode (anode). These were called Cathode Rays or Cathode Ray Particles