Tag: chemistry

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Questions Related to chemistry

Multiple choice chemistry element, compound and chemical reaction materials around us materials around us and different types of houses matter and its states

The fluorescent tubes and neon sign bulbs glow due to the presence of ____________.

  1. charged particles

  2. high voltage

  3. high temperature

  4. colour
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When an application of high voltage is provided to the electrodes, the neon gas ionizes due to the flow of $e^-$ which thereby excite the neon gas atoms and cause them to emit light. In the case of fluorescent tubes, low-pressure mercury vapour is present which emits UV light when ionized.

Multiple choice chemistry atom fundamental particles of an atom the structure of atoms discovery of subatomic particles

An αα particle is:

  1. a hydrogen molecule

  2. a helium nucleus

  3. an electron

  4. a proton
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$(B)$ a helium nucleus 


$Reason$ : An $\alpha$ particle is a positively charged particle consists of two protons and two neutrons , all held together by the same strong nuclear force that binds the nucleus of any atom , emitted by some radioactive substances and identical to the nucleus of helium atom . It carry a charge of $+2$. 

Multiple choice chemistry atom fundamental particles of an atom the structure of atoms discovery of subatomic particles

If number of electrons in an atom is 8 and number of protons is also 8, then give the atomic number of atom and the charge on the atom.

  1. (i) Atomic number = 8, (ii) Charge = 0

  2. (i) Atomic number = 4, (ii) Charge = 0

  3. (i) Atomic number = 8, (ii) Charge = +1

  4. (i) Atomic number = 4, (ii) Charge = +1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Atomic number is equal to number of protons i.e. 8. Since number of protons is equal to number of electrons i.e. 8, therefore charge on the atom is 0.

Multiple choice chemistry atom fundamental particles of an atom the structure of atoms discovery of subatomic particles

An atom does not carry any electric charge because it _____________.

  1. has an equal number of charged and non charged particles

  2. has neutrons in their nuclei

  3. has an equal number of electrons and protons, hence positive and negative charge gets neutralized.

  4. has an equal number of neutrons and protons
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Equal number of negatively charged electrons and positively charged protons would give a neutral atom which would thus not have any electric charge.