Answer:
Explanation:
3. The number of electrons and neutrons in an atom are 13 and 14, respectively. Find out the mass number, atomic number, valency, and symbol of the element.
For a neutral atom. number of protons =number of electrons=13
so since atomic number is the number of protons =13
mass number = protons + neutons =14+13 = 27
atomic number 13 is Aluminum (AL-(see periodic table)
The electronic structure for 13 electrons is 1s2s2p63s23p1
so Al has 3 electrons which are VALIENT and can react and when it loses the 3 it will have CHARGE OF +3
J. Because birds swim and fish don’t
The net force = -5 N
The direction : to the left(negative sign)
<h3>Further explanation
</h3>
Net force : the sum of all forces acting on an object
Force is a vector quantity that has both magnitude and direction,
We agree that the move up and to the right is a positive sign, while down and to the left is a negative sign.
The direction of the force (horizontal motion) is to the right (+32 N), and to the left (-37 N), so the net force :
Answer:
0.0025moles
Explanation:
Molarity of a solution (M) = number of moles (n) ÷ volume (V)
According to this question, to make 250 mL of a 0.01 M solution of CaCl, the following number of moles is needed:
Volume = 250mL = 250/1000 = 0.250Litres.
Using; molarity = n/V
0.01 = n/0.250
n = 0.0025
n = 2.5 × 10^-3 moles.
