$$40420 \text{cm}^2 \times \left(\frac{1 \text{m}}{100 \text{cm}}\$$right)^2$$ = 4.042 \text{m}^2$$

$$\text{density} = \frac{15.5 \text{g}}{2.3 \text{mL}} = 6.7 \text{g/mL}$$

$$197 \text{km} / 102 \text{min} \times 0.621 \text{mi}/1 \text{km} \times 60 \text{min}/1 \text{hr} = 72.0 \text{mph}$$

Question 1

Which component of the scientific method is most critical for ensuring the reliability of experimental results, and why?

Accepted Answer

Peer review, because it allows for independent verification and reduces bias.

Question 2

Which of the following best defines 'matter'?

Accepted Answer

Anything that has mass and occupies space.

Question 3

A student weighs a rock and finds it has a mass of 2.5 kg and a weight of 24.5 N. Which statement is correct?

Accepted Answer

Weight is the force exerted by gravity on an object, while mass is the amount of matter.

Question 4

Which of the following is a heterogeneous mixture?

Accepted Answer

Sand and iron filings

Question 5

Which property is an intensive physical property?

Accepted Answer

Density

Question 6

Which scenario describes a chemical change?

Accepted Answer

Burning wood

Question 7

Convert 40420 $$	ext{cm}^2 to$$ $$	ext{m}^2$$ using dimensional analysis.

Accepted Answer

$$40420 	ext{cm}^2 	imes \left(\frac{1 	ext{m}}{100 	ext{cm}}\$$right)^2$$ = 4.042 	ext{m}^2$$

Question 8

How many significant figures are in the measurement 0.00013 g?

Accepted Answer

2

Question 9

A metal sample has a mass of 15.5 g and increases the volume in a graduated cylinder by 2.3 mL. What is its density?

Accepted Answer

$$	ext{density} = \frac{15.5 	ext{g}}{2.3 	ext{mL}} = 6.7 	ext{g/mL}$$

Question 10

Given the isotopic symbol in the image, what does 'A' represent?

Accepted Answer

Mass number

Question 11

For the isotope $$^{204}_{81}	ext{Tl}^{1+}$$, how many electrons does it have?

Accepted Answer

80

Question 12

Which block on the periodic table does Magnesium belong to?

Accepted Answer

s-block

Question 13

Which element is a metalloid?

Accepted Answer

Silicon

Question 14

What is the complete electron configuration for Magnesium?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$ $$3s^2$$

Question 15

Dracula traveled 197 km in 102 minutes. What was his average speed in mph?

Accepted Answer

$$197 	ext{km} / 102 	ext{min} 	imes 0.621 	ext{mi}/1 	ext{km} 	imes 60 	ext{min}/1 	ext{hr} = 72.0 	ext{mph}$$

Question 16

Which of the following is a chemical property?

Accepted Answer

Ability to rust

Question 17

Which metric prefix represents $$10^{-6}$$?

Accepted Answer

micro-

Question 18

If an atom has 33 protons, 45 neutrons, and 36 electrons, what is its net charge?

Accepted Answer

-3

Question 19

Which of the following is a pure substance?

Accepted Answer

Copper metal

Understanding the Parts of an Elemental (Isotopic) Symbol

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