The alpha particle is the helium nucleus.
The mass of helium nucleus (⁴₂He) is 4u.
The mass of radioactive atom decreases by 4u. Look at the reaction below:
²²³₈₈Ra ---> ⁴₂He + ²¹⁹₈₆Rn
Question in incomplete, complete question is:
Technetium (Tc; Z = 43) is a synthetic element used as a radioactive tracer in medical studies. A Tc atom emits a beta particle (electron) with a kinetic energy (Ek) of 
. What is the de Broglie wavelength of this electron (Ek = ½mv²)?
Answer:
is the de Broglie wavelength of this electron.
Explanation:
To calculate the wavelength of a particle, we use the equation given by De-Broglie's wavelength, which is:
where,
= De-Broglie's wavelength = ?
h = Planck's constant = 
m = mass of beta particle = 
= kinetic energy of the particle =
Putting values in above equation, we get:
is the de Broglie wavelength of this electron.
Answer:
NH4+(aq) → NH3(aq) + H+(aq)
Explanation:
Following arrhenius, an acid can be defined as:
An Arrhenius acid is a substance that, when added to water, increases the concentration of H+ ions in water.
NH4+(aq) → NH3(aq) + H+(aq)
The ammonium ion acts as a weak acid in aqueous solution, dissociating into ammonia and a hydrogen ion.
An Arrhenius base is a substance that, when added to water, increases the concentration of OH- ions in water.
NH4+(aq) will not dissciate in OH- ions. So it's not a base, but an acid.
C6H6(l) + 6 Cl2(g) = C6Cl6(s) + 6 HCl(g)
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