Question

choose the best answers.
1.016) which atomic particle has no charge?
a. proton
b. neutron
c. electron
1.017) which atomic particle has a positive charge?
a. proton
b. neutron
c. electron
1.018) what is true about the air inside a balloon?
a. the particles are visible.
b. the particles are very large.
c. the air inside a balloon has no particles.
d. the particles are too small to be seen.
1.019) object x has a mass of 300 g and a volume of 150 cm³. object y has a mass of 400 g and a volume of 200 cm³. which object has a higher density?
a. object x
b. object y
c. they both have the same density.
1.020) which of the following materials is not likely to sink when placed water?
a. iron
b. aluminum
c. wood
d. gold

Explanation:

1.016

Step1: Recall charge of atomic particles

Proton has \( +1 \) charge, neutron has \( 0 \) charge, electron has \( -1 \) charge.

1.017

Step1: Recall charge of atomic particles

Proton has \( +1 \) charge, neutron has \( 0 \) charge, electron has \( -1 \) charge.

1.018

Step1: Properties of air particles

Air is made of particles (e.g., \( N_2, O_2 \) molecules). These particles are too small to be seen with naked eye.

1.019

Step1: Use density formula \(

ho=\frac{m}{V} \)
For object \( X \): \( m_X = 300g\), \( V_X=150cm^3\), \(
ho_X=\frac{300}{150}=2g/cm^3\)

Step2: Use density formula \(

ho=\frac{m}{V} \)
For object \( Y \): \( m_Y = 400g\), \( V_Y=200cm^3\), \(
ho_Y=\frac{400}{200}=2g/cm^3\)

1.020

Step1: Compare density with water

Density of water is approximately \( 1g/cm^3\). Density of iron (\(\approx7.87g/cm^3\)), aluminum (\(\approx2.7g/cm^3\)), gold (\(\approx19.3g/cm^3\)) are greater than water. Wood (density \( < 1g/cm^3\) for most types) has lower density than water.

Answer:

1.016: B. neutron
1.017: A. proton
1.018: D. The particles are too small to be seen.
1.019: C. They both have the same density.
1.020: C. wood