Answer:
Velocity is vector quantity. So it needs <em>direction</em> in addoition to <em>speed</em>.
The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of its speed and direction of motion.
<u>Answer:</u> The ion that is expected to have a larger radius than the corresponding atom is chlorine.
<u>Explanation:</u>
There are two types of ions:
- <u>Cations:</u> They are formed when an atom looses its valence electrons. They are positive ions.
- <u>Anions:</u> They are formed when an atom gain electrons in its outermost shell. They are negative ions.
For positive ions, the removal of electron increases the nuclear charge for an outermost electron because the outermost electrons are more strongly attracted by the nucleus. So, the effective nuclear charge increases for cations and thus, the size of the cation will be smaller than that of the corresponding atom.
For negative ions, the addition of electron decreases the nuclear charge for an outermost electron because the outermost electrons are less strongly attracted by the nucleus. So, the effective nuclear charge decreases for anions and thus, the size of the anion will be larger than that of the corresponding atom.
For the given options:
<u>Option a:</u> Chlorine
Chlorine gains 1 electron and form
ion
<u>Option b:</u> Sodium
Sodium looses 1 electron and form
ion
<u>Option c:</u> Copper
Copper looses 2 electrons and form
ion
<u>Option d:</u> Strontium
Strontium looses 2 electrons and form
ion
Hence, the ion that is expected to have a larger radius than the corresponding atom is chlorine.
Potassium itself is not a compound, it’s an element. Represented by “K” and has an atomic number of 19. However, it can be used to make a compound
Galvanometer:
its an instrument for detecting small electric currents.
Electric motor:
its an electrical machine that converts electrical energy into mechanical energy.
Answer:
10.5g
Explanation:
First, let us calculate the number of mole of NaHCO3 present in the solution. This is illustrated below:
Volume = 250mL = 250/1000 = 0.25L
Molarity = 0.5M
Mole =?
Molarity = mole /Volume
Mole = Molarity x Volume
Mole = 0.5 x 0.25
Mole = 0.125 mole
Now, we shall be converting 0.125 mole of NaHCO3 to grams to obtain the desired result. This can be achieved by doing the following:
Molar Mass of NaHCO3 = 23 + 1 + 12 +(16x3) = 23 + 1 +12 +48 = 84g/mol
Number of mole of NaHCO3 = 0.125 mole
Mass of NaHCO3 =?
Mass = number of mole x molar Mass
Mass of NaHCO3 = 0.125 x 84
Mass of NaHCO3 = 10.5g
Therefore, 10.5g of NaHCO3 is needed.