Average speed=total distance traveled/time. Total distance=the sum of the two short distances=79*2+77*3=389 km. Total time used to travel is 2+3=5 hr. Average speed is 389/5=77.8 km/hr.
The best use of an atomic model to explain the charge of the particles in Thomson's beams is:
<u>An atom's smaller negative particles are at a distance from the central positive particles, so the negative particles are easier to remove.</u>
<u>Explanation:</u>
In Thomson's model, an atom comprises of electrons that are surrounded by a group of positive particles to equal the electron's negative particles, like negatively charged “plums” that are surrounded by positively charged “pudding”.
Atoms are composed of a nucleus that consists of protons and neutrons . Electron was discovered by Sir J.J.Thomson. Atoms are neutral overall, therefore in Thomson’s ‘plum pudding model’:
-
atoms are spheres of positive charge
- electrons are dotted around inside
Thomson's conclusions made him to propose the Rutherford model of the atom where the atom had a concentrated nucleus of positive charge and also large mass.
Just find the density of every metal and select the one with a density of 2.71 g/cm³ . This is:
Metal 1
ρ = m/V
ρ = 22.1 g / 3 cm³
ρ = 7.367 g / cm³
Metal 2
ρ = m/V
ρ = 42 g / 4 cm³
ρ = 10.5 g / cm³
Metal 3
ρ = m/V
ρ = 9.32 g / 5 cm³
ρ = 1.864 g / cm³
Metal 4
ρ = m/V
ρ = 8.13 g / 3 cm³
ρ = 2.71 g / cm³
<h2>R / Metal 4 was selected.</h2>
Answer:
numbers
Explanation:
Virtually all unimaginable processes can be described as the movement of certain objects. To analyze and predict the nature of the movements that result from the different kinds of interactions, some important concepts such as momentum, force and energy have been invented. If momentum, force, and energy are known and expressed in a quantitative way (that is, by numbers) it is possible to establish rules by which the resulting movements can be predicted.
