The answer is focal point.
The focal length is the distance from the lens (or mirror) to the focal point. The focal point is <span>the point at which rays of light converge.</span>
Volcanic eruption most likely to happen when the plates are moving intense in the ground. Maybe an earthquake are most likely for a volcanic eruption to occur.
Answer:
The international date line is measured approximately from <u><em>180 degrees longitude</em></u>.
Explanation:
Meridians and parallels are the imaginary lines used to determine degrees of latitude and geographic longitude. They differ in that the meridians are the circumferences that pass through both poles of the globe, while the parallels are the minor circles that are parallel to the equator, and which serve as the basis for determining latitude.
An antimeridian is a meridian exactly opposite to any meridian that is taken from reference, and therefore, the resulting meridian adds 180 º to that taken from reference.
The Greenwich meridian is the one from which the degrees of geographical longitude of each place on the planet are counted over the Equator. Its name is due to the fact that the imaginary line of the 0 ° meridian that passes through the two poles of the Earth crosses the English town of Greenwich.
When taking Greenwich, 0º, as its reference meridian, its antimeridian is the one located on the opposite side to 180º. This meridian is the international date change line.
So the international date change line is an imaginary surface land line drawn over the Pacific Ocean and coincident with the 180 ° meridian.
Then, <u><em>the international date line is measured approximately from 180 degrees longitude.</em></u>
Sodium sulfide formula is Na₂S.
Na is a group 1 element, it has one valence electron therefore it is ready to give that valence electron and form an ionic bond. Once it gives out the electron it becomes a positive ion - Na⁺
sulfur is a group 6 element, has 6 electrons its outer shell and needs to gain 2 more electrons to become stable. Once it gains 2 electrons it becomes a negative ion - S²⁻.
Since Na only gives out 1 electron, S²⁻ ion needs to take in 2 electrons, therefore forms an ionic compound with 2 Na⁺ ions.
decomposition of Na₂S is as follows;
Na₂S(s) --> 2Na⁺(aq) + S²⁻ (aq)
The talk test can be used to measure the <u>intensity of an activity</u>
<u>Option: B</u>
<u>Explanation:</u>
The talk test is usually used to measure the intensity of a particular activity when a person talks during that activity. This is mostly used in cardiovascular patients to measure the intensity of the exercise.
For example, when a person can talk during exercising, it means that he is able to use the oxygen to create energy for the muscles. i.e he will be in aerobic state. Incase, he is not able to talk any more during his exercise, it means that the breathing rate has reached a particular ventilatory threshold.
So now the body is creating energy from the stored system such as muscle glucose and creatine. Thus this talk test helps to determine in which way your body creates energy, aerobic or non aerobic.