Answer:
a. atoms are the basic building blocks of matter. The atom is made of electrons and protons. It contains the chemical identity of an element.
b. Three types of particles that make up an atom are:
electrons - these are negatively charged particles and lightest constituents of an atom.
protons are positively charges and is 1873 times heavier than an electron.
Neutrons are neutral particles having mass equivalent to mass of proton.
Protons and neutrons exist in the center of an atom in nucleus and electrons revolve around the nucleus.
c. An atom is a neutral entity where as an ion is charged. An ion has excess of electrons or lacks electrons due to which it has negative or positive charge. An atom has an equal number of electrons and protons.
d. In a negative ion, the number electrons is greater than number of protons. The atom when gains electrons becomes negative ion.
e. John Dalton proposed Solid sphere model in which tiny invisible particles constitute matter. These invisible particles are atoms and these are indivisible.
The change in electric potential energy is given by:
ΔU = ΔVq
ΔU = change in PE, ΔV = potential difference, q = charge
Given values:
ΔV = 50V - 20V = 30V, q = 0.14C
Plug in and solve for ΔU:
ΔU = 30(0.14)
ΔU = 4.2J
When rounding you look at the number right after the one you want to round. The tenth place is the one right after the decimal. If the number after it is more than five it goes up by one, it it's less than five it stays the same. So since the number after the 8 is a 3 it stays the same.
The answer is 7.8
Answer:it is 343 meter per second in air.
Explanation:
it is 5 times more in liquids than in gases and 15 times more in solids than in gases.In air it is affected by various physical conditions such as pressure,humidity and temperature.
-- There are 80 protons in the nucleus of every atom of Mercury,
but only 8 of them in the nucleus of an atom of Oxygen.
-- Mercury must be warmer than 357°C in order to boil, but Oxygen
must only be warmer than -183°C.
-- Mercury must be colder than -39°C in order to freeze, but Oxygen
must be colder than -219°C.
-- Oxygen is required for human life. Mercury is a deadly poison.
