Atomic Number of Zinc is 30, means it contains 30 electrons. So, its electronic configuration is as follow,
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰
As,
1s², 2s², 2p⁶, 3s², 3p⁶ = Argon
So,
Electronic configuration of Zinc in shorthand notation is as follow,
[Ar] 4s², 3d¹⁰
Answer: 
Explanation: 1 gram is equal to 1000 Milligrams so
Since you go straight across its just multiplication so 0.00200x1000=200mg
To answer it in scientific notation it should just be mg
Answer:
D
Explanation:
In a Helium (He) atom, the atomic structure of the atom has 2 protons, 2 electrons and 2 neutrons. For an element X to be a Helium (He) atom, it must possess 2 protons. The number of neutrons present will determine its stability either if its probably radioactive or a natural occurring inert gas.
In option 1,
We have H-2. The symbol "H" is used to denote the element hydrogen in the periodic table and hydrogen has only 1 protons and 1 neutron making its mass number 2.
Option 2,
He -2 : here in this option, we have a helium atom, but with mass number of 2 only. Judging from the formula of mass number = protons + neutrons, we already have proton as 2, hence the number of neutrons there is zero (0)
Option 3,
He - 3 : just like in option 2, the only difference here is that the mass number is 3 hence making the number of neutrons just 1.
Option 4,
He - 4 : This option met the requirements of having 2 protons and 2 neutrons making a total of 4 which corresponds to the mass number.
Answer: -
C. The hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.
Explanation: -
The kinetic energy of gas molecules increase with the increase in the temperature of the gas. With the increase in kinetic energy, the gas molecules also move faster. Thus with the increase of temperature, the speed of the molecules increase.
Temperature of first hydrogen gas sample is 10 °C.
10 °C means 273+10 = 283 K
Thus first sample temperature = 283 K
The second sample temperature of the hydrogen gas is 350 K.
Thus the temperature is increased.
So both the kinetic energy and speed of molecules is more for the hydrogen gas sample at 350 K.
Thus the hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.
Hence the answer is C.
