Explanation:
sodium (Na +)
Carbonate ion (CO₃²⁻)
Ionic compounds are formed between ions (Anions and Cations).
For a neutral compound to be formed, the charges of the ions must cancel each other out.
Sodium ion has a charge of +1
Carbonate ion has a charge of -2
The only way to make sure both ions have similar charges is to multiply each ion by the coefficient of the other.
Thus we have;
Sodium ion = +1 * 2 = +2
Carbonate ion = -2 * 1 = -2
From this, the chemical formular of the product formed between both ions must contain 2 sodium ions and one carbonate ion.
This is given by;
Na₂CO3
Its B and D
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Answer:
The correct answer is - alpha particle and positron.
Explanation:
In this question, it is given that, 38^88Sr decays to 34^84Kr, which means there is an atomic number decrease by 4, 38 to 34, and atomic mass decreases by 4 as well 88 to 84.
A decrease in the atomic mass is possible only when there is an emission of the alpha particle as an alpha particle is made of 2 protons and 2 neutrons. If an atom emits an alpha particle, there is a change in atomic number as it decreases by two, and its mass number decreases by four.
So after the emission of an alpha particle, the new atom would be
38^88Sr=> 36^84X => 34^84Kr
so there is also two positron emission that leads to decrease in atomic number by one with each emission:
38^88Sr=> 2^4He+ 36^84X => 36^84X + 2(1^0β+) => 34^84Kr
Positron decay is the conversion of a proton into a neutron with the emission of a positron that causes the atomic number is decreased by one, which causes a change in the elemental identity of the daughter isotope.
Answer : The mass of water produced will be 32.78 grams.
Explanation : Given,
Mass of 
= 21.9 g
Molar mass of = 72.15 g/mole
Molar mass of 
= 18 g/mole
First we have to calculate the moles of .
Now we have to calculate the moles of .
The balanced chemical reaction will be,
From the balanced reaction we conclude that
As, 1 mole of react to give 6 moles of
So, 0.3035 moles of react to give 
moles of
Now we have to calculate the mass of .
Therefore, the mass of water produced will be 32.78 grams.
The aluminum can with stand <span>0.942 J° C of heat </span>
