Answer:
Option A = 1:1
Explanation:
The atoms of calcium and sulphur when react their ration is 1:1. The charge on calcium is +2 and on sulphur is -2.
Ca⁺²S⁻²
The +2 and -2 charges are cancel out and overall charge will be zero.
CaS
so their atomic ratio will be 1:1
B. If I add substance X, then it will lower the temperature at which water freezes.
C. People should eat vegetables.
D. Bananas are better for you than chocolate. 2: Kobe is testing whether 100 g of substance A, 100 g of substance B, or 100 g of substance C produces more oxygen in a chemical reaction at 25°C. What is the independent variable?
A. the masses of the substances
B. the temperature of the substances
C. the amount of oxygen produced
D. the nature of the substances 3: A chemist measures the amount of mercury in sediment samples from three areas of a river (the source, the midway point, and the mouth). Which of the following is the most reasonable hypothesis for the chemist's experiment?
A. If a chemical plant near the source of the river is dumping mercury, then the mercury levels should be highest at the source and lowest at the mouth.
B. If a chemical plant near the source of the river is dumping mercury, then the mercury levels should be highest at the mouth and lowest at the midway point.
C. If a chemical plant near the source of the river is dumping mercury, then the mercury levels should be highest at the mouth and lowest at the source.
D. If a chemical plant near the source of the river is dumping mercury, then the mercury levels should be the same all along the river.
The correct options are as follows:
1. B.
In scientific investigation, an hypothesis refers to a supposition that is put forward to explain an observed phenomenon. A hypothesis is described as valid if it fulfilled five different conditions. The conditions are as follows:
1. It must be capable of empirical verification.
2. It must be express clearly and it must be definite and certain.
3. It must be specific and it is predictions must be clearly expressed.
4. It must be formulated in such a way that its content can easily be translated to understand the observed phenomenon that give birth to the hypothesis.
5. It should possess theoretical relevance.
2. D.
Scientific investigations usually make use of two major variables, these are dependent variables an independent variables. The dependent variable refers to the variable whose value depend on that of another variable. The independent variable on the other hand refers to that variable whose variation does not depend on the value of another variable. In the question given above, the natures of the three substances is the independent variable because their variation is not determined by any variable.
3. B.
If a chemical plant near the source of a water body is dumping mercury inside the water, then the highest amount of mercury will be found at the mouth of the river while the lowest quantity of mercury will be found at the middle of the water. This is because as the water waves are carrying the mercury deposits away from the mouth of the river, they will disperse it evenly in the river and thus its concentration will reduce compare to that present at the mouth of the river. The highest amount of mercury is found at the mouth of the river because that is where the mercury enters the water.
b. the energy required to remove an electron from the element in its gaseous state
c. the energy released by the element in forming an ionic bond
d. the energy released by the element upon receiving an additional electron
e. none of the above
The ionization energy is energy required to remove an electron from element in it's gaseous state.
Ionization energy is defined as the minimum energy required to remove an electron from its valence shell of an isolated gaseous atom,positive ion or molecule.Ionization energy is positive for neutral atoms from which it can be concluded that ionization is an endothermic process.
Closer are the valence electrons to nucleus ,higher is the ionization energy.It is usually expressed in electron volts or joules.Ionization energy increases from left to right in a period as more energy is required to remove electrons with small atomic size.
Ionization energy decreases down the group as atomic size increases due to which electrons are easily lost from the valence shell.
Learn more about ionization energy ,here:
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A. S.
B. N.
C. Sn.
D. Na.
Answer:
bromine is reduced
Explanation:
Works on Gradpoint
B) dispersion.
C) refraction.
D) resolution.
B. the small intestine
C. the heart
D. the large intestine