Answer:A) It was developed from past observations- true
It is subject to experimentation and revision.- false
It explains why mass is conserved- false
It predicts future observations-true
Explanation:
Before a hypothesis is proclaimed to be a law in science, numerous observation must have confirmed its validity and rigorous experimentation under carefully controlled conditions usually precedes the acceptance of a hypothesis as a law. The law of conservation of mass was developed from numerous past observation that proved its validity.
Answer:
No
Explanation:
Betelgeuse has a diameter around 700 times the size of our sun…. like possibly as far as the orbit of Jupiter. It is known as a red supergiant and around 100,000 times brighter than our sun. Betelgeuse is at the very end of its life.
Hey there!
Molar mass Na2SO4 = 142.04 g/mol
Number of moles:
n = m / mm
n = 25 / 142.04
n = 0.176 moles of Na2SO4
Therefore, use the Avogadro constant
1 mole Na2SO4 ------------------- 6.02x10²³ molecules
0.176 moles Na2SO4 ------------ molecules ??
0.176 x ( 6.02x10²³ ) / 1
=> 1.059x10²³ molecules of Na2SO4
hope this helps!
Answer:
Isotopes of an element have same number of protons but different number of neutrons. Which means isotopes of an element have same atomic number but different mass number.
The chemical property of an element is determined by the number of electrons. And as all the isotopes have same number of electrons, they have same chemical properties.
Thus as isotopes of an element have same atomic number , they have same number of electrons and protons. As they have different mass number, the number of neutrons will be different. Hydrogen has three isotopes , 
, 
and 
. Thus has no neutron.
