There are 12<span> protons and </span>10<span> electrons in a </span><span>Mg<span>2+</span></span><span> ion, the normal amount of neutrons is </span>12<span>.</span>
The easiest way to approximate ph level is through the ph paper measurement system because using pH paper would be best for doing a quick measurement in the field. It does not essentially need to be calibrated or standardized and the papers make available an instant estimate.
<h2>Answer : Option A) Field lines enter Earth near the North Pole.</h2><h2>Option D) Field lines circle Earth from east to west. and </h2><h2>
Option E) A compass can lead a hiker to the geographic North Pole.</h2><h3>Explanation :</h3>
A) The earth's magnetic field lines are observed to enter near the north pole because it is the magnetic pole; which is the point were the magnetic field lines are vertical and enter the earth.
D) The magnetic field line are believed to start from east and end in west similar to the meridians.
E) The Earth is considered as a magnet which seems to interact with other magnets in a way, so the north end of a compass magnet is drawn to align with the Earth's magnetic field.
Answer:
A chemical change occurred and a gas was produced.
Step-by-step explanation:
If there is no chemical reaction, the <em>Law of Conservation of Mass</em> says that
Total mass = Mass 1 + Mass 2
However, if the two liquids react and give off a gas, then
Total mass = Mass 1 + Mass 2 + Mass of gas
You are not measuring the mass of the gas, so the mass of the liquids after mixing is less than it was before mixing.
For example, if Liquid 1 was a solution of HCl and Liquid 2 was a solution of Na₂CO₃, they would give off CO₂ on mixing. but you would not be measuring the mass of the CO₂.
The amount of heat lost by granite is equal to the amount
of heat gained by water. Therefore their change in enthalpies must be equal.
The opposite in sign means that one is gaining while the other is losing
ΔH granite = - ΔH water
ΔH is the change in enthalpy experienced by a closed object
as it undergoes change in energy. This is expressed mathematically as,
ΔH = m Cp (T2 – T1)
Given this information, we can say that:
12.5 g * 0.790 J / g ˚C * (T2 – 82 ˚C) =
- 25.0 g * 4.18 J / g ˚C
* (T2 – 22 ˚C)
9.875 (T2 – 82) = 104.5 (22 – T2)
9.875 T2 – 809.75 = 2299 – 104.5 T2
114.375 T2 = 3108.75
T2 = 27.18 ˚C
The temperature of 2 objects after reaching thermal
equilibrium is 27.18 ˚<span>C.</span>