6. Which formula could you use according to the scenario? Five grams of substance occupy 3 cm3 of a flask. Om = du OD Ot= d

Which scientist first made a model of the atom called the plum pudding model? John Dalton J.J. Thomson Neils Bohr Ernest Rutherf

Norma-Jean [14]

Answer: J.J Thomson

Explanation: J. J. Thomson, who discovered the electron in 1897, proposed the plum pudding model of the atom in 1904 before the discovery of the atomic nucleus in order to include the electron in the atomic model.

6 0

2 years ago

A car has two horns, one emitting a frequency of 199 hz and the other emitting a frequency of 203 hz. what beat frequency do the

andriy [413]

Beat frequency, fb = |f2-f1|

That is, beat frequency is the absolute difference between two frequencies. Is is as a results of destructive and constructive inferences.

Therefore, in this case:

fb = 203 - 199 = 4 Hz

3 0

2 years ago

For every O ion, two Na ions are needed to balance charges. Which ratio represents the relationship between Na and O? 1 Na:1 O 1

quester [9]

For every O ion, two Na ions are needed to balance charges. Which ratio represents the relationship between Na and O?

2 Na:1 O

6 0

3 years ago

Read 2 more answers

Match the indices of refraction with the corresponding effects on the waves.

Yanka [14]

Answer:

B) waves speed up

C) waves bend away from the normal

Explanation:

The index of refraction of a material is the ratio between the speed of light in a vacuum and the speed of light in that medium:

$n=\frac{c}{v}$

where

c is the speed of light in a vacuum

v is the speed of light in the medium

We can re-arrange this equation as:

$v=\frac{c}{n}$

So from this we already see that if the index of refraction is lower, the speed of light in the medium will be higher, so one correct option is

B) waves speed up

Moreover, when light enters a medium bends according to Snell's Law:

$n_1 sin \theta_1 = n_2 sin \theta_2$

where

$n_1 ,n_2$ are the index of refraction of the 1st and 2nd medium

$\theta_1,\theta_2$ are the angles made by the incident ray and refracted ray with the normal to the interface

We can rewrite the equation as

$sin \theta_2 = \frac{n_1}{n_2}sin \theta_1$

So we see that if the index of refraction of the second medium is lower ( $n_2$ ), then the ratio $\frac{n_1}{n_2}$ is larger than 1, so the angle of refraction is larger than the angle of incidence: