Science Quiz #861

Science and Nature Quiz for 16 July 2025

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Q1. The six most abundant ions in seawater are chloride (Cl −), sodium (Na +), sulphate (SO4 2−), magnesium (Mg 2+), calcium (Ca 2+), and what?

Silicon (Si)

Bromine (Br -)

Phosphorus (P)

Potassium (K +)

Select from the options above.

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Q2. The United Nations designated the 2020s as the "Decade of Ocean Science for... (what)"?

Carbon Absorption

Sustainable Development

Halting Extinctions

Eliminating Plastic

Select from the options above.

Uh oh, did we make a mistake? Or perhaps you enjoyed learning something new! Good or bad, we welcome your feedback. Before submitting a correction, please consider the following:

Have you re-read the question to ensure you didn't overlook anything? Example: a question asking what is 'not' an example of something.
For brevity, we avoid adding clarification where we feel the intention is clear. Example: Which city has the largest population? We're looking for the largest of the four options, not the largest globally. Example: Which city is north of another? Choose the city that is due north over the one due east, even if the latter is a little to the north too.
Options can be eliminated if they are invalidated by the question. Example: We ask you to select the largest English city and we've included Paris in the options. That is a clue!
Have you done a quick search to confirm that your feedback is correct? You'd be surprised how many people don't!
Politeness goes a long way in encouraging us to consider your point of view.

Thank you for taking the time to get in touch! Rest assured we review every comment we receive.

Q3. What would you use to neutralise an acid?

Alkali

Alcohol

Water

Fire

Select from the options above.

Uh oh, did we make a mistake? Or perhaps you enjoyed learning something new! Good or bad, we welcome your feedback. Before submitting a correction, please consider the following:

Have you re-read the question to ensure you didn't overlook anything? Example: a question asking what is 'not' an example of something.
For brevity, we avoid adding clarification where we feel the intention is clear. Example: Which city has the largest population? We're looking for the largest of the four options, not the largest globally. Example: Which city is north of another? Choose the city that is due north over the one due east, even if the latter is a little to the north too.
Options can be eliminated if they are invalidated by the question. Example: We ask you to select the largest English city and we've included Paris in the options. That is a clue!
Have you done a quick search to confirm that your feedback is correct? You'd be surprised how many people don't!
Politeness goes a long way in encouraging us to consider your point of view.

Thank you for taking the time to get in touch! Rest assured we review every comment we receive.

Q4. A placenta in which the umbilical cord is attached at the placental margin is called what?

Battledore placenta

Placenta previa

Placenta accreta

Placenta increta

Select from the options above.

Uh oh, did we make a mistake? Or perhaps you enjoyed learning something new! Good or bad, we welcome your feedback. Before submitting a correction, please consider the following:

Have you re-read the question to ensure you didn't overlook anything? Example: a question asking what is 'not' an example of something.
For brevity, we avoid adding clarification where we feel the intention is clear. Example: Which city has the largest population? We're looking for the largest of the four options, not the largest globally. Example: Which city is north of another? Choose the city that is due north over the one due east, even if the latter is a little to the north too.
Options can be eliminated if they are invalidated by the question. Example: We ask you to select the largest English city and we've included Paris in the options. That is a clue!
Have you done a quick search to confirm that your feedback is correct? You'd be surprised how many people don't!
Politeness goes a long way in encouraging us to consider your point of view.

Thank you for taking the time to get in touch! Rest assured we review every comment we receive.

Q5. Nicotine is named after the tobacco plant Nicotiana tabacum, which got its name from what or whom?

Saint Nicholas

Jean Nicot de Villemain

Nico (Christa Päffgen)

Tsar Nicholas I

Select from the options above.

Uh oh, did we make a mistake? Or perhaps you enjoyed learning something new! Good or bad, we welcome your feedback. Before submitting a correction, please consider the following:

Have you re-read the question to ensure you didn't overlook anything? Example: a question asking what is 'not' an example of something.
For brevity, we avoid adding clarification where we feel the intention is clear. Example: Which city has the largest population? We're looking for the largest of the four options, not the largest globally. Example: Which city is north of another? Choose the city that is due north over the one due east, even if the latter is a little to the north too.
Options can be eliminated if they are invalidated by the question. Example: We ask you to select the largest English city and we've included Paris in the options. That is a clue!
Have you done a quick search to confirm that your feedback is correct? You'd be surprised how many people don't!
Politeness goes a long way in encouraging us to consider your point of view.

Thank you for taking the time to get in touch! Rest assured we review every comment we receive.

Q6. What is the Keeling Curve?

The relationship between socio-economics and recycling

The optimum curve for a ship's keel

A graph of fluctuations in a stock market

A graph of variation and overall accumulation in global atmospheric carbon dioxide concentration

Select from the options above.

Uh oh, did we make a mistake? Or perhaps you enjoyed learning something new! Good or bad, we welcome your feedback. Before submitting a correction, please consider the following:

Have you re-read the question to ensure you didn't overlook anything? Example: a question asking what is 'not' an example of something.
For brevity, we avoid adding clarification where we feel the intention is clear. Example: Which city has the largest population? We're looking for the largest of the four options, not the largest globally. Example: Which city is north of another? Choose the city that is due north over the one due east, even if the latter is a little to the north too.
Options can be eliminated if they are invalidated by the question. Example: We ask you to select the largest English city and we've included Paris in the options. That is a clue!
Have you done a quick search to confirm that your feedback is correct? You'd be surprised how many people don't!
Politeness goes a long way in encouraging us to consider your point of view.

Thank you for taking the time to get in touch! Rest assured we review every comment we receive.

Q7. What is the next number in this sequence: 4; 16; 256; 65,536?

9,244,967,629

4,296,967,294

4,294,967,296

14,294,967,296

Select from the options above.

Uh oh, did we make a mistake? Or perhaps you enjoyed learning something new! Good or bad, we welcome your feedback. Before submitting a correction, please consider the following:

Have you re-read the question to ensure you didn't overlook anything? Example: a question asking what is 'not' an example of something.
For brevity, we avoid adding clarification where we feel the intention is clear. Example: Which city has the largest population? We're looking for the largest of the four options, not the largest globally. Example: Which city is north of another? Choose the city that is due north over the one due east, even if the latter is a little to the north too.
Options can be eliminated if they are invalidated by the question. Example: We ask you to select the largest English city and we've included Paris in the options. That is a clue!
Have you done a quick search to confirm that your feedback is correct? You'd be surprised how many people don't!
Politeness goes a long way in encouraging us to consider your point of view.

Thank you for taking the time to get in touch! Rest assured we review every comment we receive.

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