Answer:
Some substances dissolve when you mix them with water. When a substance dissolves, it might look like it has disappeared, but in fact it has just mixed with the water to make a transparent (see-through) liquid called a solution.
Explanation:
Mass of X₂O₇ = 54,9g
2x + 33,6g = 54,9g
2x = 54,9g - 33,6g
2x = 21,3g | :2
x = 10,65g/mol
C and A because the product of a matter will always be the same and just google A.
Answer:
Chemical reaction are irreversible. Some of the example of chemical reaction are cooking, rusting, and burning. During a chemical reaction, the composition of substances changes and the particles rearrange to form a new substance. The new substance formed after chemical reaction of substance has different physical and chemical properties.
When a chemical reaction occur, the atoms or molecules of the substances change its physical and chemical properties such as while cooking of vegetable, the molecules of vegetable undergo changes in their properties and form a new substance which is different from the earlier.
<h3>Answer:</h3>
Strontium (Sr)
<h3>Explanation:</h3>
The condition given in statement is the presence of two valence electron. Hence, first we found the electronic configuration of given atoms as follow;
Rubidium [Kr] 5s¹
Strontium [Kr] 5s²
Zirconium [Kr] 4d² 5s²
Silver [Kr] 4d¹⁰ 5s¹
From above configurations it is cleared that only Strontium and Zirconium has two electrons in its valence shell.
We also know that s-block elements are more reactive than transition elements due to less shielding effect in transition elements hence, making it difficult for transition metals to loose electrons as compared to s-block elements. Therefore, we can conclude that Strontium present in s-block with two valence electrons is the correct answer.
