Since the atomic number of calcium is 20. The number of protons is also 20.
Answer:
give me brainliest pls
Explanation:
Volumetric flasks
Volumetric labware is for measuring liquids with precision. Volumetric flasks, burettes, and pipettes made for measuring small amounts of liquid are the most accurate, with tolerances of less than ±0.02.
Half-life is basically how long it takes for a radioactive molecule to get to 1/2 of its original mass.
so if sodium 24 mass was 5g and it's half life was 24years then:
after every 24years 1/2 of 5g would have decayed. so in 48years there will only be 2.5g left.
Answer:
The lowest whole number mass ratio of nitrogen that combines with a given mass of oxygen is 1:1
Explanation:
In compound A, we have 14 g of nitrogen combine with 16 g of oxygen
In compound B, we have 14 g of nitrogen combine with 32 g of oxygen
Therefore, we have
A B
Ratio of molar masses 14:16 14:32
Mass of O that combine with 1 g of N 1.14 2.29
Dividing by the smallest mass ratio 1 2
Therefore the lowest whole number mass ratio at which oxygen and nitrogen can combine = 1:1.
Answer:
129 units cubed
Explanation:
There are ten spaces between 120 and 130, so we can infer that each line represents a change in volume of 1 unit. The volume of the substance in the graduated cylinder looks like it's 1 under 130, so its volume is 129 units.
Hopefully this was helpful! :)
