Answer:
Oxygen is an element that can be a solid, liquid or gas depending on its temperature and pressure. In the atmosphere it is found as a gas, more specifically, a diatomic gas. This means that two oxygen atoms are connected together in a covalent double bond.
For any pure substance, the boiling point and melting point will always remain sharp or distinct. This is because the substance has uniform properties all throughout. Hope this answers the question. Have a nice day. Feel free to ask more questions.
Answer:
Explanation:
Before the Rutherford's model of the atom, the plum pudding model proposed by J.J Thomson through his experiment using the gas discharge tube was the prevalent structure of the atom known.
Through Thomson, it was widely and popularly believed that the atom is made up of a pool of negatively charged particles.
When Rutherford performed the Alpha scattering experiment using a thing gold foil, he observed that all the alpha particles passed through the thin gold foil and just a few of them were deflected back.
To explain this, the suggested the atomic or nuclear model of that atom in which an atom has a small positively charged center called nucleus where all the mass is concentrated.
Today, the suggestion that an atom is made up of nucleus is highly relevant and still consistent.
Answer:
D
Explanation:
Moji could've chosen hardness tests that were not reliable.
Answer:
B.The linear velocity of the gears is the same. The linear velocity is 432π centimeters per minute.
Explanation:
As we know that the small gear completes 24 revolutions in 20 seconds
so the angular speed of the smaller gear is given as
Now we know that the tangential speed of the chain is given as
so we have
Since both gears are connected by same chain so both have same linear speed and hence correct answer will be
B.The linear velocity of the gears is the same. The linear velocity is 432π centimeters per minute.
