Answer:
elements are composed of
electrons with a little mass and negative charge
protons with mass and positive charge
neutrons with mass and no charge
isotopes same number of protons, different in neutrons
share me the other part of the photo to complete!!!
The average speed is calculated using the following formula
Where
T = 298 K [room temperature]
m = mass of each molecule of oxygen
mass of one mole of oxygen molecules = 32 g / mol
mass of one molecule of oxygen will be = 
mass of one molecule of oxygen will be = 
putting values
average speed = 
Average speed = 482.19 m / s
average speed = 1735.8 km / h
so approx = 1700 km/h
Mass of electrons are not included when calculating the atomic mass of element. Atomic mass of the element is equal to proton + neurons. Example the the mass number of Nitrogen can be calculated as 7 protons + 7 neutrons to give 14 . thus nitrogen has a mass number of 14
W=(m'/m)·100%
m'=37.2 g
m=48.5 g
w=(37.2/48.5)·100%=76.7%
Answer:
D 30
Explanation:
whenever there is a reaction, the amount of atoms don't change, because matter can't be created or destroyed. Add the carbon and oxygen atoms together
