Answer:
D) she is confident and has already made plans
Endothermic reaction is the answer.
Changes in matter occur every day. There are two types of ways matter can be altered; physically and chemically. Physical changes do not change the composition of the matter while chemical changes occur when one or more substances turn into a completely new substance. Physical changes can be seen through an altering of the substances physical property. A substances physical property is observed and measured without changing the composition of the subject. Descriptive words that would help to identify a substance’s physical property include hard, soft, brittle, flexible, heavy, and light just to name a few. Let’s say you’re eating, throughout the day your stomach starts to growl that is what happens when your stomach is digesting your food. Digestion is an example of chemical change. Chemical change happens every day and more than half the time we don’t realize it whether it’s metal starting to rust, or our food starting to rot. Physical change can happen when your popsicle starts to melt, or your water starting starting to boil. These are examples of physical change.
The empirical formula of compounds formed from the given ions are as follows:
- Pb⁴⁺ = PbO₂
- NH₄⁺ = NH₄Cl
- CrO₄²⁻ = Na₂CrO₄
- SO₄²⁻ = K₂SO₄
<h3>What is the empirical formula of a compound?</h3>
The empirical formula of a compound is the simplest formula of the compound showing the simplest ratios in which elements in the compound combine.
The empirical formula of compounds formed from the given ions are as follows:
- Pb⁴⁺ = PbO₂
- NH₄⁺ = NH₄Cl
- CrO₄²⁻ = Na₂CrO₄
- SO₄²⁻ = K₂SO₄
In conclusion, the empirical formula is the simplest formula of a compound.
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