Answer:
The fulcrum of the metre stick is at the 40 cm mark
100 g * 10 cm = 1000 g-cm clockwise torque
x * 30 cm = 1000 gm-cm = counterclockwise torque for balance
X = 1000 / (40 -10) = 1000 / 30 = 33.3 gm at 10 cm to balance
Answer:
35 neutrons are in an atom of copper
A. acceleration.
On a Velocity vs Time graph the slope will always be equal to the acceleration. I.e. if the slope is negative, so is the acceleration and vice versa.
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+
6.10 x 10^9 / 3 x 10^5 = 2.033 x 10^4 seconds = 20.33 / 3.6 = nearly 6 hours
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