<h2>
Answer: # of neutrons = 9</h2>
<h3>
Explanation:</h3>
# of neutrons = mass number - atomic number
= 17 - 8
= 9
<h3>∴ number of neutrons in an atom of oxygen of mass number 17, is 9.</h3>
Answer: Ethyl Ethanoate can be used as a developing solvent. It’s safer.
Explanation:Di ethyl ether should be carefully used because it’s highly flammable and intoxicating when inhaled and can cause explosions because of its high reactivity to air and light.
Answer:
The atomic mass of gallium (Ga) = <u>69.723 g/mol</u>
Explanation:
Given: Two isotopes of Gallium (Ga) are Gallium-69 (⁶⁹Ga) and Gallium-71 (⁷¹Ga)
<u>For ⁶⁹Ga: </u>
Relative abundance = 60.12% = 60.12 ÷ 100 = 0.6012; Atomic mass = 68.9257 g/mol
<u>For ⁷¹Ga:</u>
Relative abundance = 39.88% = 39.88 ÷ 100 = 0.3988; Atomic mass = 70.9249 g/mol
∴ The atomic mass of Ga = (Relative abundance of ⁶⁹Ga × Atomic mass of ⁶⁹Ga) + (Relative abundance of ⁷¹Ga × Atomic mass of ⁷¹Ga)
⇒ Atomic mass of Ga = (0.6012 × 68.9257 g/mol) + (0.3988 × 70.9249 g/mol) = <u>69.723 g/mol</u>
<u>Therefore, the atomic mass of gallium (Ga) = 69.723 g/mol</u>
The straight horizontal line shows us that the object is moving at a constant speed
Answer:
The answer to your question is: Includes sulfur and gain two electrons
Explanation:
Includes Chlorine This option is wrong, Chlorine belongs to group VII.
Includes Sulfur This option is true, Group VI includes Oxygen, Sulfur, Selenium, Tellurium.
Gain 2 electrons
. This option is true, Elements in group VI have six valence electrons so they gain to electrons to become estable.
Tend to form +2 ions This option is wrong, this elements form -2 ions
Have 5 valence electrons This option is wrong, this elements have 6 valence electrons.
