Answer:
In his alien language, he said ¨ Hellooooo human¨
Explanation:
Yes. They are called compound machines because two or more simple machines were combined to create it.
Answer: The correct option is 2.
Explanation: Polyatomic ions are defined as the ions in which two or more elements are covalently bonded to act as a single unit. They always carry some charge.
Examples of polyatomic ions are: 
known as hydroxide ion, 
known as sulfate ion
We are given a compound 
having 2 ions which are 
and 
. these ions are named as sodium ions and hydrogen carbonate ions.
Therefore, the correct option is 2.
Answer:
The higher up an object is the greater its gravitational potential energy. ... As most of this GPE gets changed into kinetic energy, the higher up the object starts from the faster it will be falling when it hits the ground. So a change in gravitational potential energy depends on the height an object moves through.
Answer:
839 g
Explanation:
We know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.
M_r: 81.97 209.94
NaAlO₂ + … ⟶ Na₃AlF₆ + …
Mass/g: 2150
1. Calculate the <em>moles of Na₃AlF₆
</em>
Moles of Na₃AlF₆ = 2150 × 1/209.94 Do the operation
Moles of Na₃AlF₆ = 10.24 mol Na₃AlF₆
2. Calculate the <em>moles of NaAlO</em>₂
The molar ratio is 1 mol NaAlO₂:1 mol Na₃AlF₆
Moles of NaAlO₂ = 10.24 × 1/1 = 10.24 mol NaAlO₂
3. Calculate the <em>mass of NaAlO₂
</em>
Mass of NaAlO₂ = 10.24 × 81.97 Do the multiplication
Mass of NaAlO₂ = 839 g
