Answer: The statement is true
Explanation:
The half-life of a radioactive isotope is the time taken for half of the total number of atoms in a given sample of the isotope to decay.
For instance
The half-life of radium is 1622 years. This means that if we have 1000 radium atoms at the beginning, then at the end of 1622 years, 500 atoms would have disintegrated, leaving 500 undecayed radium atoms
Thus, the statement is true
Answer:
Titanium (III) bromide
Explanation:
As it is an ionic compound we write the valency for transition elements, and that means here that titanium loses three electrons to become +3 (Ti
Answer:
Convection is the process of heat transfer in which hotter and therefore less dense matter floats to the top, while cooler and therefore more dense material sinks to the bottom to absorb heat.
Explanation:
Convection is one form of heat transfer; other forms include conduction and (heat) radiation (not exactly the same as the kind uranium emits).
This form of heat transfer is characterised by a use of current in a liquid, in which the sinking and rising create a current which has a shape of a loop.
This requires an outside source of heat, since to sustain the current, once the heated fluid rises up, it must lose heat to the environment to sink, but to rise it must gain heat again.
Hydrogen gas and oxygen gas react to form liquid water according to the following equation:
2H₂ + O₂ → 2H₂O
a. Converting our given masses of each gas to moles, we have:
(25 g H2)/(2 × 1.008 g/mol) = 12.4 mol H2; and
(25 g O2)/(2 × 15.999 g/mol) = 0.781 mol O2.
From the equation, two moles of H2 react with every one mole of O2. To fully react with 12.4 moles of H2, as we have here, one would need 6.2 moles of O2, which is far more than what we're actually given. Thus, the oxygen is our limiting reactant, and as such it will be the first reactant to run out.
b. Since O2 is our limiting reactant, we use it for determining how much product, in this case, H2O, is produced. From the equation, there is a 1:1 molar ratio between O2 and H2O. Thus, the number of moles of H2O produced will be the same as the number of moles of O2 that react: 0.781 moles of H2O. The mass of water produced would be (0.781 mol H2O)(18.015 g/mol) ≈ 14 grams of water (the answer is given to two significant figures).
c. Since the hydrogen reacts with the oxygen in a 2:1 ratio, twice the number of moles of oxygen in hydrogen is consumed: 0.781 mol O2 × 2 = 1.562 mol H2. Since we began with 12.4 moles of H2, the remaining amount of excess H2 would be 12.4 - 1.562 = 10.838 mol H2. The mass of the excess hydrogen reactant would thus be (10.838 mol H2)(2 × 1.008 g/mol) ≈ 22 grams of hydrogen gas (the answer is given to two significant figures).
Answer:
water and vinegar
:salad
Explanation:
There is two kind of mixture the heterogeneous and homogeneous mixture.Which water and vinegar is the homogeneous and the salad is heterogeneous mixture based on my example above.
