What class is this? (Subject)
Answer:
D
Explanation:
When lead ions and sulfate ions bond, they form sediment so neither a nor b can be the answer.
The important thing is that two nitrate ions were originally bonded with one lead ion, while two potassium ions bonded with a sulfate ion.
Finally, since potassium and nitrate ions don't form sediment these two ions must remain. Therefore the answer is D
Answer:
internal fertilization
Explanation:
Internal fertilization enhances the fertilization of eggs by a specific male. Fewer offspring are produced through this method, but their survival rate is higher than that for external fertilization.
Explanation:
Elements in the same group have same number of valence electrons. And we know, the elements which have same number of valence electrons, have similar physical and chemical properties. Hence, the elements in the same group have similar physical and chemical properties.
<span>The answer to the question is the option C. it cannot be physically broken down into different types of atoms. This means that the material is an element, which is a pure substance. Because an element is a pure substance that is formed by one only type of atoms. For example, gold is an element and all its atoms are of the same type. That is also true for any of the 118 elements of the periodic table. Compounds (other kind of pure substances) can be broken down into molecules (which contain different kind of atoms, but always in the same proportion) and mixtures (non pure substances) have different kind of substances.</span>