The answers are
The age of the oldest stars
How fast distant galaxies are moving away from us
Patterns of background radiation.
Explanation:
The Astronomers calculate the age of the universe by looking for oldest stars, and by measuring the rate of expansion of the universe and back to big bang.
The Astronomers used the techniques like the age of oldest stars, how fast the distant galaxies are moving away from us, patterns of background radiation and along with the Big Bang as reference point, they estimate that the universe may be approximately 12 billion years old.
we are asked in this problem to determine the mass of a liquid in a small container. In order to determine the mass, we use an analytical balance for greater accuracy by first weighing the whole system (liquid+beaker). Then transfer the liquid to another container and completely dry the beaker (wash and dry). measure the weight of the beaker. The mass of the liquid is equal to the mass of the system minus the mass of the beaker.
Answer:
7
Explanation:
N-14 has 7
i looked it up ye ur probably gonna get it right
Answer:
Heated water is more dense than melted snow because water as liquid is denser than ice. Ice floats on water, which means that it has less density than water. Heated water is warmer and more dense than melted ice.
Explanation:
Answer:
2.94
Explanation:
There is some info missing. I think this is the original question.
<em>A solution is prepared at 25 °C that is initially 0.38 M in chloroacetic acid (HCH₂ClCO₂), a weak acid with Ka= 1.3 x 10⁻³, and 0.44 M in sodium chloroacetate (NaCH₂CICO₂). Calculate the pH of the solution. Round your answer to 2 decimal places.</em>
<em />
We have a buffer system formed by a weak acid (HCH₂ClCO₂) and its conjugate base (CH₂CICO₂⁻ coming from NaCH₂CICO₂). We can calculate the pH using the Henderson-Hasselbalch equation.
pH = pKa + log [CH₂CICO₂⁻]/[HCH₂ClCO₂]
pH = -log 1.3 x 10⁻³ + log (0.44 M/0.38 M)
pH = 2.94
