A controlled experiment is one in which evrerything is held constant except for one verieble, maybe is usually a st of data is taken for a control group.
Answer:D. 2.61 x 10^22
Explanation:
Given that mass of Lead(Pb) = 8.97g
Molar mass of lead =207.2g/mol
No of moles = Mass / molar mass
=8.97g/207.2g/mol
= 0.04329moles
Converting to atoms using Avogadro's number
we know that
1 mole = 6.022 x 1023 atom
Therefore 0.04329 moles of Pb = 0.04329moles x 6.022 x 10^23 atoms
=2.6069 x 10^22
=2.61 x10^22atoms
Answer:homogeneous mixture
A sandstorm is a homogeneous mixture.
Explanation:
The three reasons that scientists found Rutherfor's nuclear atomic model to be fundamentally incomplete are as follows:
Number 1) according to Rutherford, the electrons revolve in completely
circular orbits. However, if this was true the charged electron would
simply fall into the nucleus after losing energy.
Number 2)
According to Rutherford's model, the nucleus itself only consisted of
protons. However, as we now know due to research in quantum mechanics,
if this was true this would make the atom unstable due to the cycle of
attraction and repulsion.
Number 3) The neutrons which have also
been discovered since to be an important part of the atom, are not
mentioned at all in Rutherford's model.
Earth is the right distance from the sun. It’s protected from harmful solar radiation by its magnetic field and the atmosphere keeps it warm. Earth contains the right chemical ingredients to sustain life such as H2O (water) and C (carbon)