Answer:
Explanation:
Use the position of an element in the periodic table to deduce its valence.
The periodic table is a table that groups elements based on their periodic functions. A group is a vertical arrangement of elements. The group number shows the number of elements in the outer shell of the atoms.
The groups runs from 1 to 8. On the periodic table, elements that has more than 4 electrons in their outermost shell will have a valency of 8 less than the number of outermost electrons.
Write formulas for these hydrides without using subscripts, for example XH3. If no hydride forms, write "none".
for group I : NaH, KH,
group II : MgH2, CaH2,
group III: BH3, AlH3
Group 8 do not form hydrides because of their inertness.
What is the formula of the hydride formed by sulfur?
the hydride of sulfur is H₂S
What is the formula of the hydride formed by potassium ?
the hydride of potassium is KH
Because the molecules are more closely spaced, the solid occupies less space than the same substance when it is in a gaseous state.
Answer:
THE DISTANCE OF THE ROCK REFLECTING HER VOICE IS 82.5 METERS.
Explanation:
In sound waves, the speed of a sound is equal to twice the distance divided by time.
Mathematically,
Speed = 2 * Distance/ Time
Speed = 33- m/s
Time = 0.5 second
Distance = unknown
So re-arranging and introducing the variables into the formula, we have;
Distance = speed * time / 2
Distance = 330 * 0.5 / 2
Distance = 82.5 meters.
The distance away from the rock face which is reflecting her voice is 82.5 meters.
The amount of heat (in calories) needed to raise the temperature is 324.885 calories
<h3>How to determine the temperature change </h3>
We'll begin by obtaining the temperature change. This can be obtained as followed:
- Initial temperature (T₁) = 14 °C
- Final temperature (T₂) = 25 °C
- Change in temperature (ΔT) = ?
ΔT = T₂ - T₁
ΔT = 25 - 14
ΔT = 11 °C
<h3>How to determine the heat (in Calories)</h3>
The amount of heat needed to raise the temperature can bee obtaimedals follow:
- Mass (M) = 33 g
- Change in temperature (ΔT) = 11 °C
- Specific heat capacity (C) of diethyl ether = 0.895 cal/g°C
- Heat (Q) =?
Q = MCΔT
Q = 33 × 0.895 × 11
Q = 324.885 calories
Thus, the amount of heat needed is 324.885 calories
Learn more about heat transfer:
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