Answer: B
Oxygen acts as oxidator in the first reaction.
Explanation:
At reactant side:
Mg = 0
At product side:
MgO = 0
but Oxygen (O) = -2
Mg + O = 0
Mg + (-2) = 0
Mg - 2 = 0
Mg = 2
Magnesium is oxidized by OXYGEN from zero to +2
Oxygen acts as oxidator in the first reaction.
Answer:
I believe that the best example of rotational motion is : B. The wheel spins as long as the hamster keeps running.
Explanation:
Rotational motion refer to a rotation movement, which means the main axis point stays the same.
Answer:
D. It would have a net negative charge
Explanation:
In an atom, there are electrons, protons and neutrons collectively called SUBATOMIC PARTICLES. The charge of an atom is determined by the number of electrons and protons in that atom. A neutral or uncharged atom possess the same number of electrons and protons.
The charge can thus be calculated as follows:
Charge of atom = no. of protons - no. of electrons.
Hence, when the number of electrons in an atom is higher than that of the protons, it means that the atom has gained negatively charged electrons, making that atom have a net negative charge. For example, In an atom that contains 10 protons and 11 electrons, the charge of that atom will be (10 - 11) = -1. The net charge of that atom will be -1, which is NEGATIVE.
Explanation:
Expression for the coefficient of thermal expansion is as follows.
where, V = initial volume
= Final volume - initial volume
= (712.6 - 873.6) 
= -161
Now, we will calculate the change in temperature as follows.
= Final temperature - Initial temperature
= (10 + 273) K - (70 + 273) K
= 283 K - 343 K
= -60 K
Substituting these values into the equation as follows.
= 0.00307 
It is known that for non-ideal gases the value of alpha is 0.366% which is 0.00366 per Kelvin. As it is close to our result, hence the given sample of gas is a non-ideal gas.
Answer is D - Argon atom
Potassium has atomic number as 19. Hence, number of protons = 19
If the atom is neutral,
number of protons = number of electrons = 19
Hence, the electron configuration of potassium (K) is
1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
Potassium ion is formed by losing an electron. Then the number of electrons = 19 - 1 = 18
Electron configuration of K⁺ is 1s² 2s² 2p⁶ 3s² 3p⁶.
This is same as the electron configuration of Ar which has 18 electrons.
