Atomic number is written in subscript:
Uranium atomic number =92
Mass of neutron is the superscript value times the quantity (moles):
3*1= 3
Atomic mass is approximately equivalent to the number of protons and neutrons in the atom (the mass number). It's written in superscript:
Kr=92
No. of neutrons = Mass number (in superscript) - Atomic number ( in subscript)
= 141-56= 85
No. of neutrons in reactants are: 3
Answer:
Yes
Explanation:
Atoms are generally classified as pure substances. A pure substance has the following properties:
- All parts are the same throughout i.e. homogeneous
- They have definite composition
- The cannot easily be broken down into simpler substances by physical means.
- Separation by physical methods is not easy.
- They have unique sets of physical properties.
Elements and compounds are generally classified as pure substances. Since atoms are the building blocks of pure substances, they can be classified as one.
Atomic radius decreases across a period because valence electrons are being added to the same energy level at the same time the nucleus is increasing in protons. The increase in nuclear charge attracts the electrons more strongly, pulling them closer to the nucleus.
The equation is one to one so you can use M1V1=M2V2
so
(30ml)(.10M)=(25ml)(x)
x= .12M
The weight of the balloon is irrelevant because it is the gas that lifts it in the air. We are already given with the required volume, so we use this instead. The atomic weight of zinc is 65.38 g/mol. Assuming ideal gas behavior,
PV=nRT
P(475 mL)(1 L/1000 mL) = (1.85/65.38)(0.0821 L·atm/mol·K)(21.5 + 273)
P = 1.44 atm
Then, we use this pressure and the volume to find the moles of zinc.
(1.44 atm)(475 mL+1 mL)(1 L/1000 mL) = n(0.0821 L·atm/mol·K)(21.5 + 273)
Solving for n,
<em>n = 0.02836 moles of zinc</em>
