Answer:
Initial pressure = 157 kpa (Approx)
Explanation:
Given:
final temperature = 234 K
final pressure = 210 kpa
Initial temperature = 175 K
Find:
Initial pressure
Computation:
Initial pressure / Initial temperature = final pressure / final temperature
Initial pressure / 175 = 210 / 234
Initial pressure = 157 kpa (Approx)
Brass is an alloy, or a combination of two (or more) metals.
Answer:
There are significant environmental impacts associated with coal mining and use. It could require the removal of massive amounts of top soil, leading to erosion, loss of habitat and pollution. Coal mining causes acid mine drainage, which causes heavy metals to dissolve and seep into ground and surface water.
Explanation:
Answer:
There are 2.5 * 10^22 beryllium atoms in 0.37 grams
Explanation:
Step 1: Data given
The mass of an atom of beryllium is 1.5 x 10^-26 kg.
Total mass = 0.37 grams
Step 2: Calculate number of atoms
1 atom = 1.5 * 10 ^-26 kg
X atoms = 0.00037 kg
X = 0.00037/1.5*10^-26
X = 2.467 * 10^22 atoms ≈ 2.5 * 10^22 atoms
There are 2.5 * 10^22 beryllium atoms in 0.37 grams
Answer:
27.7 × 10²³ atoms
Explanation:
Given data:
Number of moles of Potassium = 4.6 mol
Number of atoms = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For 4.6 moles of K:
One mole = 6.022 × 10²³ atoms
4.6 mol × 6.022 × 10²³ atoms= 27.7 × 10²³ atoms
