Selenium has 36 electrons34(atomic number) + 2(amount of electrons gained in the <span>ion, has a 2- charge) = 36
</span>To identify the number of electrons an element has, all you need is a periodic table. Identify the atomic number (the smallest of the 2 numbers in the box). That number will be the number of protons which is also the number of electrons.
*number Atoms of all elements are made up of three primary particles: protons, neutrons, and electrons. The "sub-atomic" particles each have specific properties that such as size, electrical charge, etc. that are crucial for the stability of the atom. The particles break down like this: Particle Relative size Charge Location How to determine
Proton 1 + in the nucleus # of protons= element's atomic # (use periodic table)
Electron 0 - outside nucleus # of electrons=# of protons(in neutral, "normal" atom)
Neutron 1 0 in the nucleus Must be told or given (ie. can vary--isotopes--
for small elements most common form often
consists of isotope where #protons=#neutrons) Aluminum has 13 electrons because it needs 13 negative charges to balance the 13 postively-charged protons (which is what the periodic table told us it contains). This will make the Aluminum atom electrically neutral.
Boomerang has a curve the airplane propeller is four paddles
Answer:
Time elapsed = 2.856
SECOND ROCK HAS FASTER SPEED
Explanation:
This can be achieved in 2 ways, and it is clear from the careful study that the travel time is attributed to the time required to cross the path above the bridge by the 2nd stone i.e.
14 = 9.8 * t
t = 1.428 sec and
time between 2 splash = 2 * 1.428 = 2. 857 sec
2nd way
let time for 1st spalsh be t and
second splash be t1.
from equation of motion
so 60 = 14t + 0.5 * 9.8 * t * t
4.9 t^2 + 14t -60 = 0
On solving, we get t = 2.351 sec
for t_1, we have some extra time, which can be divided into t2 and t3.
14 = 9.8 * t2
t2 = 1.428 sec
total time taken by 2 is
T = 1.428 + 1.428 + 2.351
so we get t_1 = 5.207 sec
time elapsed is = T - t
= 5.207 - 2.351
Time elapsed = 2.856
SECOND ROCK HAS FASTER SPEED
Answer:
A) 20 N, B) 20 N, & C) 8 N
Explanation:
For the object to be in equilibrium, the upward forces must be equal to the downward forces and the forward forces must be equal to the backward forces.
1. Determination of A and B.
Forward forces = Backward forces
A + 10 + B = 25 + 25
A + 10 + B = 50
Collect like terms
A + B = 50 – 10
A + B = 40
Assume A and B to be equal. Thus, A is 20 N and B is 20 N.
2. Determination of C
Upward forces = Downward forces
C + 112 = 20 + 100
C + 112 = 120
Collect like terms
C = 120 – 112
C = 8 N
Thus, for the object to be in equilibrium, A must be 20 N, B must be 20 N and C must be 8N.
Answer:
8
Explanation:
Finding time= t=change in velocity or distance/acceleration
so 32/9.5-5.5
32/4
8
