The greek philosopher democritus coined what word for a tiny piece of matter that cannot be divided?
a - element
b - atom
c - electron
d - molecule

according to john dalton's observations, when elements combine in a
a - the ratio of their masses is always the same.
b - each element contributes an equal number of atoms.
c - their volumes are always equal.
d - their masses are always equal.

j. j thomson's experiments provided evidence that an
a - is the smallest particle of matter.
b - contains negatively charged particles.
c - has a negative change.
d - has a positive change.

which statement best describes rutherford's model of the atom?
a - it is like an avocado with the pit representing the nucleus.
b - it is like a aquarium with swimming fish representing positive charges.
c - it is like a fried egg with the yolk representing the nucleus.
d - it is like a huge stadium with positively charged marble at the center.

Greek philosopher Democritus coined the term atom. Atom is derived from a Greek word atomos which means that it can not be cut. According to him, every matter is made up of tiny particles called  atom.

Hence the correct answer to the first question is B-Atom.

According to Dalton's postulates, every matter consists of tiny spherical and indivisible particles called atom. Atoms of a specific element are same in size,mass and properties and varies from a different element.When a compound is formed,atoms always combine with other atoms with a fixed ratio

Hence the correct answer to the second question will be-A - The ratio of their masses is always the same.

J.J Thomson discovered electron from his Crooke' s tube experiment.The charge of electron is always negative .

Hence the correct answer to the third question will be B - Contains negatively charged particles.

As per Rutherford's atomic model, an atom consists of a massive positively charged core called nucleus.The total mass of the atom is appeared to be concentrated there. The electrons are revolving around the nucleus just like planets are revolving around the sun. The positive charge of the nucleus is due to the presence of protons. Most of the spaces in atom is empty.

As per the options given in the question,a huge stadium can be considered as atom.The the positively charged marble at the centre may considered as nucleus.

Hence the correct answer to this question will be D - It is like a huge stadium with positively charged marble at the center.

the average speed is 24.57 km/hr

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..