Check answers?
1) Why did J.J. Thomson reason that electrons must be a part of the atoms of all elements?
A) Cathode rays are negatively charged particles****
B) Cathode rays can be deflected by magnets
C) An electron is 2000 times lighter than a hydrogen atom
D) Charge-to-mass ratio of electrons was the same, regardless of the gas used
2) Who conducted experiments to determine the quantity of charge carried by an electron?
A) Rutherford
B) Millikan
C) Dalton****
D) Thomson
3) What is the relative mass of an electron?
A) 1/1840 the mass of a hydrogen atom
B) 1/1840 the mass of a neutron + proton***
C) 1/1840 the mass of a C-12 atom
D)1/1840 the mass of an alpha particle
4) All stable atoms are ____.
A) positively charged, with the number of protons exceeding the number of electrons
B) negatively charged, with the number of electrons exceeding the number of protons
C) neutral, with the number of protons equaling the number of electrons
D) neutral, with the number of protons equaling the number of electrons, which is equal to the number of neutrons*****
To check the answers, let's go through each question:
1) Why did J.J. Thomson reason that electrons must be a part of the atoms of all elements?
The correct answer is A) Cathode rays are negatively charged particles. Thomson reasoned that since cathode rays (electron beams) were observed to be negatively charged, electrons must be a part of the atoms of all elements.
2) Who conducted experiments to determine the quantity of charge carried by an electron?
The correct answer is B) Millikan. Millikan conducted the oil drop experiment, which allowed him to measure the quantity of charge carried by an electron.
3) What is the relative mass of an electron?
The correct answer is A) 1/1840 the mass of a hydrogen atom. The relative mass of an electron is approximately 1/1840 the mass of a hydrogen atom.
4) All stable atoms are __.
The correct answer is C) neutral, with the number of protons equaling the number of electrons. All stable atoms are electrically neutral, meaning they have an equal number of protons and electrons. The number of neutrons does not affect the overall charge of the atom.