Answer:
Solution
The atomic number of iodine (53) tells us that a neutral iodine atom contains 53 protons in its nucleus and 53 electrons outside its nucleus. Because the sum of the numbers of protons and neutrons equals the mass number, 127, the number of neutrons is 74 (127 − 53 = 74). Since the iodine is added as a 1− anion, the number of electrons is 54 [53 – (1–) = 54].
Check Your Learning
An ion of platinum has a mass number of 195 and contains 74 electrons. How many protons and neutrons does it contain, and what is its charge?
Answer:
78 protons; 117 neutrons; charge is 4+
Answer:
It is a copy of an object and appears to be coming from behind the mirror.
Explanation:
- The plane mirror has a flat surface, where of its surface is polished to reflect the light.
- The plane mirror shows the image as the same size of the object.
- The image produced by the plane mirror is virtual and erect.
- But the orientation of the image formed changes the left and right.
- Hence,the image appears to be coming from behind the mirror.
Answer:
It is one of the 7 diatomics
Explanation:
Br
I
N
Cl
H
O
F
^ these are the 7 diatomic molecules. Atoms of these elements exist as a molecule consisting of two covalently bonded atoms of the same element.
Simply put, for these elements, the diatomic state of the atom is much more stable than the unbound one.
At the instant you dropped it from your hand, its speed was zero.
The coin gained 9.8 m/s every second it fell. At the end of 1.85 sec,
just before it went 'tink' onto the ground, its speed was
(9.8 m/s) x (1.85 sec) = 18.13 m/s .
Its velocity at that final instant was 18.13 m/s downward.
