particles and atoms

Question 1

what is the Law of Conservation of Mass?

Answer 1

a

Question 2

what is the law of conservation of composition

Answer 2

a

Question 3

what is the particle theory of matter? what were the limits?

Answer 3

• all matter is made of particles
• particles at a higher temperature move faster than particles at a lower temperature
• particles attract each other
• particles of the same substance are different in size and mass than substance of other elements

Question 4

what is Dalton’s atomic theory?

Answer 4

• all matter is made of small particles called atoms
• atoms of the same element are different in size and mass than atoms of another element
• atoms cannot be destroyed, created, or divided into smaller pieces
• compounds are different elements chemically linked together that can be decomposed to separate elements again

Question 5

what are the 4 atomic models?

Answer 5

1) plum pudding model
2) planetary model
3) Bohr’s model
4) electron cloud model

Question 6

what’s the deal with atoms? atomic mass? atomic number? mass number?

Answer 6

a

Question 7

what are the elements? compounds?

Answer 7

a

Question 8

what is electrolysis?

Answer 8

a

Question 9

what is a binary molecular compound? How do you name it?

Answer 9

a

Question 10

what is a diatomic molecule?

Answer 10

a molecule made of two atoms of the same element

Question 11

what is an ionic compound? how do you name it?

Answer 11

a

Question 12

what’s an ion?

Answer 12

an atom that’s lost or gained an electron that gives it a negative or positive charge.

Question 13

why was the plum pudding model discarded?

Answer 13

In the radioactive sample, it emits a beam of alpha particles through a gold tin foil. Rutherford found that some of the particles went through the gold foil, some bounced back, some were deflected. he concluded that atoms were mostly made of space and that the mass is concentrated in the middle of the atom.

Question 14

why was the planetary model discarded?

Answer 14

1) his model failed to explain why individual atoms produced discrete spectra of light. According to rutherford’s model, if electrons were to accelerate in orbit, it would mean that it would produce electromagnetic radiation with high frequencies, meaning they would produce a continuous light spectrum. It was proven wrong when Bohrs put rarified gases, where the pressure is very low, and when he increased the energy, they were emitting a line spectrum of light. Only some colours were produced. he concluded that different atoms produce different colours of the line spectra.
2) according to Maxwell’s theory of electromagnetism, the electrons accelerating in orbit will produce energy in the form of light. The electron would then lose kinetic energy, which then decreases velocity. With the decreases of velocity, the electron would not stay in orbit and instead spiral into the atomic nucleus and crash. That would imply that atoms are not stable.

Question 15

what is emit?

Answer 15

produce

Question 16

velocity

Answer 16

the speed of something in a given direction

Question 17

What was the experiment that discarded the planetary model?

Answer 17

1) using a gas-discharge tube and accelerating low-density gases with a high voltage, it was observed that atoms emitted a discrete light spectrum or line spectrum. This was because each atom emits and absorbs only certain wavelengths of light that are unique to that atom.

The circular orbit would cause the electron to accelerate and emit wide frequencies of electromagnetic radiation. This means that atoms would emit a continuous light spectrum.

Question 18

Why was the Bohr model discarded?

Answer 18

according to the Uncertainty principle, it is not possible to know the exact position of an electron at the exact time.